Nicolas Berman
email: nicolas.berman@univ-amu.fr.

Mathieu Couttenier
email: mathieu.couttenier@ens-lyon.fr.

Nathalie Monnet
email: nathalie.monnet@unige.ch.

Rohit Ticku
email: ticku@chapman.edu.

Shutdown policies and conflict worldwide *

Keywords: Covid-19, Coronavirus, Conflict, Violence JEL classification: D74, E65, J18

We provide evidence on the impact of Covid-19 restriction policies on conflicts worldwide. We combine daily information on conflict events and government policy responses to limit the spread of coronavirus to study how demonstrations and violent events vary following shutdown policies. We use the staggered implementation of restriction policies across countries to identify the dynamic effects in an event study framework. Our results show that imposing a nation-wide shutdown reduces the number of demonstrations, which suggests that public demonstrations are hampered by the rising cost of participation. However, the reduction is short-lived, as the number of demonstrations are back to their pre-restriction levels in two months. In contrast, we observe that the purported increase in mobilization or coordination costs, following the imposition of Covid-19 restrictions, has no impact on violent events that involve organized armed groups. Instead, we find that the number of events, on average, increase slightly following the implementation of the restriction policies. The rise in violent events is most prominent in poorer countries, with higher levels of polarization, and in authoritarian countries. We discuss the potential channels that can explain this heterogeneity.

Introduction

On March 31st, 2020 the U.N. Secretary General, Antonio Guterres, cautioned that the coronavirus epidemic could lead to "enhanced instability, enhanced unrest, and enhanced conflict". The ongoing epidemic can exacerbate conflict by upending social and political protections. The effect could be severe for the vulnerable populations: those caught up in war and persecution, or those living in densely populated areas with dismal state capacity. 1 Critically, countries have responded with varying degree of restrictions to limit the spread of coronavirus. The policy response to Covid-19 can itself have a bearing on conflict situations. Anecdotal evidence suggests that mobility restrictions to flatten the epidemic curve, that raise the cost of mobilization and coordination, have a direct and negative effect on conflict. For instance, anti-corruption protests in Iraq and Lebanon came to a screeching halt following the announcement of the pandemic, 2 while India's lockdown terminated nationwide protests against the mistreatment of Muslims. 3 The flipside is rising scapegoating of minorities or vulnerable groups, especially when states are preoccupied with combating the pandemic. 4 Moreover, authoritarian regimes could also use the global preoccupation with coronavirus as an opportunity to crush armed opposition. For example, the Myanmar military stepped up its offensive against ethnic armed rebel groups in Rakhine, Chin, Karen and northern Shan state, 5 while the United Nations appealed for a global ceasefire to countervail the escalation in violence. 6 Some regimes may also use the global epidemic as an opportunity to stifle democratic opposition. In Azerbaijan, members of the opposition parties were locked up for allegedly violating a lockdown. 7 The Covid-19 pandemic and the subsequent restriction policies have also negatively affected economic activity. The World Bank has forecasted the global economy to shrink by 5.2% in 2020, which would earmark the worst recession since the Second World War. 8 The decline in per capita incomes can push millions of people worldwide into extreme poverty. The effect of restrictions on conflict through the income mechanism is a priori ambiguous. On the one hand, the current economic downturn may lead to more conflict, by reducing the individual opportunity cost of violence, protests and rebellions (Becker, 1968; Grossman, 1991; Dal Bó and Dal Bó, 2011), and by hampering the capacity of the state to fight opponents or buy off opposition 1 Shared responsibility, global solidarity: Responding to the socio-economic impacts of Covid-19 (UNSDG, March 2020, url). 2 A great and sudden change: the global political violence landscape before and after the Covid-19 pandemic (ACLED, August 4th, 2020, url).

3 Would-be autocrats are using Covid-19 as an excuse to grab more power (The Economist, April 23, 2020, url). 4 For example, there have been a few incidents of physical violence against Muslims, in addition to hateful messages on social media, since it was discovered that a Muslim religious gathering was the source of many coronavirus cases (The Economist, April 23th, 2020, url). Among Rohingya refugee camps in Bangladesh coronavirus is being attributed as divine punishment for women's "dishonorable acts" and not observing Purdah (veiling) (International Organization of Migration, April 19th, 2020, url).

5 Myanmar military steps up attacks as coronavirus spreads (AlJazeera, April 16th, 2020, url). 6 While some warring groups have responded to a call for ceasefire, in many of the most fragile situations there has not been any let up in fighting, and in some cases the fighting has intensified (UN.org, April 3rd, 2020, url). 7 Would-be autocrats are using Covid-19 as an excuse to grab more power (The Economist, April 23th, 2020, url).

8 COVID-19 to Plunge Global Economy into Worst Recession since World War II, World Bank (June 8th, 2020, url). (Berman et al., 2011, Fearon and Laitin, 2003). On the other hand, states with more limited resources are less attractive "prizes" to be seized, which may lead to a decrease in conflict intensity (Bates et al., 2002; Besley and Persson, 2010).9

In this paper, we provide real-time evidence on how enforcing restrictions to limit the spread of coronavirus affects conflicts globally and how conflict dynamics vary across types of events, and depend intrinsically on socio-economic or institutional contexts. We take advantage of the joint release of daily information on conflict events by the Armed Conflict Location and Event dataset, on the one hand, and on government policy responses by the Oxford Covid-19 Government Response Tracker, on the other hand, to estimate how restriction policies have affected dynamic of conflict outcomes. We use a difference-in-differences strategy that exploits the cross-country variation in the timing of restriction policies. Studying how restriction policies shape conflict behavior is subject to its own methodological challenges. First, estimates are likely to be biased because the covid-19 pandemic dynamics, and how people responded to it, can be systematically different between countries that implemented restriction measures and the non-implementing countries (Goodman-Bacon and Marcus, 2020). Second, countries have implemented a host of measures to contain the pandemic spread, which makes comparison in terms of the policy treatment difficult (Goodman-Bacon and Marcus, 2020).

We assuage the first concern by implementing a flexible event study design, where we compare the preshutdown conflict trends between the treatment and the control groups. Specifically, we regress conflict outcomes on a set of binary indicators that range from 120 days before and 120 days after the set of restriction policies. In our baseline estimates, we control for the timing of the Covid-19 outbreak to eliminate the possibility that conflict actors may scale down activity in response to the pandemic (Farboodi et al., 2020).

We further include country-specific time trends to account for trends in initial country characteristics, such as income levels or population density, that can jointly determine the pandemic and the conflict dynamics.

We alleviate the second concern, i.e. whether countries are comparable in terms of policies implemented, by estimating the conflict dynamics around specific restriction policies. In sensitivity checks we compare the evolution of conflict events around eight types of restrictions -which include policies like shelter-in-place, closure of schools, restriction on internal move, etc. -separately.

We uncover a compelling pattern of conflict dynamics around restriction policies depending on the nature of the conflict. For demonstrations, we find three striking results. First, we observe a sharp decline in demonstrations, that involve spontaneous acts of protests or rioting, following the imposition of restriction policies. The magnitude of the effect is sizable: our estimates translate into a decline by 0.8 demonstration events per day during the first month, which is substantial compared to the sample average of 1.5 events. Our results are robust to a battery of sensitivity checks, and especially, to the inclusion a full set of interactions between restriction indicators and a measure of country-specific media freedom, which alleviates concern that the decline in demonstrations can be driven by short-term constraints on media reporting. Overall, the evidence is in line with the literature on protests which suggests that public demonstrations are hampered by factors that raise the opportunity cost of participation (Madestam et al., 2013; Kurrild-Klitgaard, 2013).

Second, the reduction is short-lived, as the number of demonstrations are back to their pre-restriction levels in the second month, and remain there in the subsequent periods. Third, this U-shaped dynamic is similar across regions, when we consider specific restriction measures, and across countries with different socio-economic or institutional contexts. We further explore whether the return to pre-pandemic propensities due to countries relaxing the mobility or social distancing constraints could explain the resurgence in demonstrations. Restricting the sample to countries that imposed the restriction policies for at least three months, we observe a similar resurgence in demonstration activity, suggesting that the easing of mobility constraints is not the first-order determinant of the resurgence. Our results suggest that the short-lived effect for demonstrations could be due to two non-exclusive explanations: the negative impact of restriction policies on the economy could have fueled public resentment,10 or individuals may have overtime discounted the potential health risk from the pandemic. We consider both interpretations as equally plausible, since our data does not help to identify the most relevant one.

In contrast, we observe that the purported increase in mobilization or coordination costs, following the imposition of Covid-19 restrictions, have no impact on violent events that involve organized armed groups.

If anything, we find that the number of events, on average, increases slightly following the implementation of the restriction policies. The negligible impact of restriction policies on violent events, though, masks a significant heterogeneity. First, we observe little effect of restriction policies on violent events in Latin America, while we uncover a positive impact in Asia and Africa. We also consider the impact across specific restriction policies and find that the surge in violent events is mostly in response to the imposition of shelter-in-place and restrictions to internal movements policies. Second, we assess whether countries where the roots of conflict are present -such as countries with high poverty, ethno-religious strife or non-democratic institutions -are particularly susceptible to a rise in violent events following the Covid-19 restrictions. We find a rise in violent events in poorer countries, which could be due either to the lower opportunity cost of fighting (Becker, 1968; Grossman, 1991; Dal Bó and Dal Bó, 2011) or the lower state capacity to fight armed opposition (Berman et al., 2011, Fearon and Laitin, 2003). The escalation in violent events is also more conspicuous in countries with higher ethno-religious polarization or fractionalization, which is in line with evidence that pandemics provide a pretext for the scapegoating of minorities (Voigtländer and Voth, 2012; Jedwab et al., 2019). Finally, we find that authoritarian countries are more amenable to violent conflicts in the aftermath of Covid-19 restrictions. This result is consistent with evidence that authoritarian leaders are incentivized to repress their challengers, especially when the "world is not watching" (Durante and Zhuravskaya, 2018).

Our paper contributes to the literature in several ways. We contribute to research on the consequences of Covid-19. Ongoing research has assessed the macroeconomic implications of Covid-19 (Atkeson, 2020; McKibbin and Fernando, 2020; Guerrieri et al., 2020), the role of climate, or mass media in spreading

Covid-19 (Carleton and Meng, 2020; Bursztyn et al., 2020). Notably, Chinazzi et al. (2020) study the effect of travel restrictions on the spread of Covid-19. Closest to our study, our exercise complements the analysis in Bloem and Salemi (2020), who investigate the links between Covid-19 and conflict using a number of country-specific case studies. Our approach pools many countries together, and by doing so ignores a number of potentially important sources of heterogeneity; on the other hand, we hope to uncover regularities that can help to understand and anticipate some of the main threats associated with the current restrictions. Next, we contribute to the literature on infectious diseases and civil conflicts, which shows that health shocks from infectious diseases can potentially cause civil conflicts (Cervellati et al., 2017). We instead highlight that policy response to an epidemic can have an unintended consequence for civil conflicts. We finally contribute to the literature that draws a distinction between conflict events based on the actors involved or on the choice of tactics (Leventoğlu and Metternich, 2018; Chenoweth et al., 2011; Chenoweth and Cunningham, 2013; Stephan and Chenoweth, 2008). We complement this literature by highlighting a significant heterogeneity in the drivers of conflict that involve general public versus those which involve organized armed groups.

The next section discusses the theoretical channels and anecdotal evidence to motivate the relationship between covid-19 restrictions and conflict outcomes. Section 3 presents the data and our baseline research design. Section 4 discusses the results and their robustness, and section 5 concludes.

2 Covid-policies and conflict: channels and anecdotal evidence

Channels

Roots of conflict. Covid-19 related restriction policies may impact conflict risk through multiple channels (Rohner, 2020). They may directly affect the "deep determinants" of conflict, i.e. the incentives for particular groups and individuals to engage in disputes that may turn into violent conflict. The most direct impact of such policies is a peace-inducing one: through social distancing and limited mobility, restrictions increase mobilization and coordination costs, which in turn reduces the scope for organized violence.

Yet, these policies may at the same time increase conflict risk. First, by slowing down economic activity, they lower income and aggravate poverty (e.g. Martin et al., 2020). The effect of restrictions through the income mechanism is a priori ambiguous. On the one hand, the current economic downturn may lead to more conflict, by reducing the individual opportunity cost of violence, protests and rebellions (Becker, 1968; Grossman, 1991; Dal Bó and Dal Bó, 2011), and by hampering the capacity of the state to fight opponents or to buy off opposition (Berman et al., 2011, Fearon and Laitin, 2003). On the other hand, states with more limited resources are less attractive "prizes" to be seized, which may lead to a decrease in conflict intensity (Bates et al., 2002; Besley and Persson, 2010). A second channel is the potential exacerbation of ethnic or religious tensions generated by the policies' implementation. In particular, Covid-related restrictions may lead to the scapegoating of minorities or vulnerable groups, especially when state resources are diverted to combat the pandemic. Third, some regimes and political leaders have also used the global epidemic as an opportunity to stifle democratic opposition, restrict freedom of assembly, or increase surveillance of societies (Coyne and Yatsyshina, 2020). This may lead to more acute repression and violence in the short-run, and to a degradation of democratic institutions. Finally, Covid-19 restrictions may trigger shifts in the balance of power, which has an ambiguous effect on conflict. In workhorse contest models, a more balanced power implies more conflict (Rohner and Thoenig, 2020). Starting from low levels of conflict due to a large potential cost of rebellion (Esteban and Ray, 2008), a small shift in the balance of power due to the restriction policies (such as due a negative shock to the state capacity) can result in a significant escalation of conflict. This channel is of particular relevance for highly polarized countries.11

Bargaining failures. Another way of thinking about the consequences of Covid-related restrictions on conflict is through the lens of bargaining. Low income or ethnic (or religious) grievances affect individuals' and armed groups' incentives to engage in conflict, by changing the expected costs, gains, or fighting technologies.

Yet, conflict eventually occurs only if peaceful bargaining is not achieved. In situations where the conditions for disputes and conflict already pre-exist (e.g. poor, socially polarized countries with autocratic institutions), conflict may become more likely during the Covid-19 pandemic because the associated policies have reduced the scope for a peaceful resolution of disputes. Conflict theories generally mention three main sources of bargaining failures (Jackson et al., 2009): asymmetric information, agency problems, and commitment issues. All three could in principle be affected in the Covid-19 context. First, access to war zones may be restricted, and opportunities of conflict mediation may become more limited. Second, the uncertain impact of restrictions makes it more difficult for government to credibly commit to specific transfers aiming at avoiding conflict. Next, as mentioned previously, the costs of repression may decrease at the same time as policies are implemented, as international attention is diverted from these actions, and as leaders can legitimize them on account of implementing strict policies. This may affect the individual cost/benefit perceived by leaders and make conflict resolution more difficult.

These two ways of conceptualizing the nexus between Covid-19 policies and conflict lead to different predictions, which we take to the data. The first prediction is that, on average, Covid-related restrictions have an ambiguous impact on organized violence. The overall effect depends on the type of policies and on the magnitude of their effect on the deep determinants of conflict -fighting technologies, expected (opportunity) costs and benefits. In the empirical analysis, we consider the case of general indexes of policy restrictions as well as specific policies. The second prediction is that Covid-related restrictions may be more likely to trigger violence in contexts where the roots of conflicts are already present: countries with non-democratic institutions, high levels of poverty, or group polarization. To determine the suitability of this prediction, we estimate whether the effect of restrictions vary across countries which are different in these dimensions at the beginning of our sample period.

Types of conflicts.

A large literature in political science highlight that conflict outcomes could be determined by armed combat or non-violent campaigns (Stephan and Chenoweth, 2008; Chenoweth et al., 2011; Chenoweth and Cunningham, 2013). Conflict events can differ both in the types of actors involved (civilians vs armed groups) or in the choice of tactics (peaceful demonstrations vs violent attacks). 12 We may expect conflict to react differently to Covid-19 restriction policies depending on the nature of the conflict. For instance, Covid-19 restriction policies are likely to hamper demonstrations by increasing the cost of mobilization for the common public. 13 However, a subsequent increase in economic deprivation due to Covid-19 restrictions could foment public dissent against the state. Hence, there could be a U-shaped response of public protests or riots to the imposition of restriction policies. The impact of restriction policies on armed conflict is more nuanced and it is likely to be determined by the (opportunity) cost of fighting, the prize of victory and the balance of power between the participants. In the empirics, we separately assess the effect of Covid-related restrictions on demonstrations and armed conflicts.

Anecdotal evidence

Covid restriction ends a protest and creates another: For three months prior to the covid-19 outbreak, hundreds of student activists and working-class women had been protesting the passing of the Citizen

12 Leventoğlu and Metternich (2018) present a conceptual framework to explain the difference in types of actors that engage in violent and non-violent dissent. Lower class citizens are more likely to join rebel organizations and use violent tactics against the state, since the opportunity cost of participating in violent combat is lower. Middle class citizens, whose opportunity cost of participating in anti-government activities is higher, are more likely to oppose the state through peaceful protests or demonstrations. 13 The conjecture is consistent with evidence that political demonstrations are affected by changes in the private cost of participation (Kurrild-Klitgaard, 2013; Madestam et al., 2013).

Amendment Act (CAA), which was viewed as discriminatory against the Muslim minorities in India. 14 On March 22, the Indian Prime Minister, Narendra Modi, imposed a nationwide lockdown in response to the covid-19 outbreak. The months long anti-CAA agitation came to an abrupt end following the lockdown announcement. The imposition of a nationwide lockdown however created another crisis as millions of migrant workers were rendered jobless and away from home. Riots broke out in many parts of the country, as stranded migrant workers demanded provision of public transport services to return home. 1516 Rebel group uses Covid-19 restriction to attack state forces: On March 23, the Islamist insurgent group Boko Haram carried out a grievous attack on an army base in Chad, in which 92 soldiers were killed. On March 24th, Boko Haram insurgents ambushed a military convoy and killed 47 soldiers in Nigeria. 17 Both the events occurred just days after Covid-related restrictions were imposed in the respective countries. The escalation in violence suggested that Boko Haram was using the state's pre-occupation with Covid-19 as an opportunity to step up attacks and to recruit new members (Berman et al., 2020).

Covid restriction flames religious tension:

In early March, an international conference brought thousands of Muslim missionaries to Indian capital Delhi. On March 22, local authorities shut down the conference premises in response to cases of coronavirus infection among the participants. As missionaries returned home they became a conduit for spreading coronavirus across different parts of the country. 18 The event and the subsequent media reporting created a widespread resentment against ordinary Muslims. There were incidents of physical violence against Muslims, in addition to hateful messages on the social media. 19 Political leader uses Covid-19 restriction to stifle opposition: In Venezuela, President Nicolás Maduro's government used the emergency powers, acquired to contain covid-19 crisis, to stifle dissent. 20 The government used different tactics such as raids on private property, arbitrary detentions and media smear campaigns to target political opponents. On April 2, the government announced a Furia Bolivariana campaign, which purported to protect Chavismo from its opponents. Over a hundred incidents that targeted the opposition supporters were documented following the announcement. The ensuing climate of fear has diminished political mobilization against the incumbent regime. This was evident during the parliamentary elections held on December 6, which were boycotted by twenty seven opposition parties and experienced a 14 How the coronavirus lockdown impacted anticitizenship law protests in India, Peninsula Press (June 18th, 2020, url). 15 Charged in lockdown riot cases, migrant workers afraid to return to Gujarat, Firstpost (October 8, 2020, url). 16 Similar patterns where observed in Irak. Beginning October 2019, a wave of anti-government protests engulfed the city of Baghdad. The protest movement, popularly known as the 'Tishreen Revolution', was directed against rampant corruption and at the government's failure to create employment. The public protests came to a halt due to the covid-19 outbreak and the subsequent lockdown, but resentment against the government's inept handling of Covid crisis and a worsening economic situation eventually resulted in renewed protests. Episodes of violence, and thousands of protesters marching down the streets thus marked the one-year anniversary of the original protest.

17 Boko Haram kills troops in 'deadliest' Chad raid, BBC (March 25, 2020, url).

18 How Tablighi Jamaat event became India's worst coronavirus vector, AlJazeera (April 7, 2020, url). 19 Would-be autocrats are using Covid-19 as an excuse to grab more power, The Economist (April 23th, 2020, url). 20 How Maduro Is Using Covid-19 to Silence His Opponents Even Further, Americas Quarterly (July 21, 2020, url).

low voter turnout. 21 President Maduro led coalition won an overwhelming majority in the disputed elections and has strengthened its grip on power.

The preceding four vignettes, of course, do not constitute an exhaustive catalogue of Covid-related conflicts.

Still, they help us to envision different channels through which Covid-related restrictions could impact conflict events worldwide. We explore these linkages more formally in the subsequent empirical analysis.

3 Data and empirical strategy

Data and stylized facts

Conflict. We use conflict event data from the Armed Conflict Location and Event dataset (Raleigh et al., 2010, acled, hereafter), which we extracted from the acled website on September 12, 2020. The data contain daily information on conflict events with specific details on the nature and the actors on both sides of the conflicts. Events are compiled from various sources, including press accounts from regional and local news, humanitarian agencies, and research publications. 22 Our analysis focuses on 134 countries, for which

Covid-restrictions data is also available, from January 1st 2016 to September 1st 2020 (see Online Appendix Table A1.1 for a full list of countries). We do not consider the last ten days of data (September 2-12, 2020), as it is likely that reporting of events for this period was still incomplete when we retrieved the data. 23

In our estimations, we consider two broad categories of conflict events as defined by acled, irrespective of whether acled identifies them as directly related to Covid-19: "violent events" and "demonstrations". 24

"Violent events" include battles, violence against civilians and remote violence, and are carried out by armed groups with a political objective. On the other hand, "demonstrations" are spontaneous actions with a political motive and include protests and riots by the public. The two event categories thus differ in the nature of the actors involved: the former consists of organized armed groups or states, while the latter involves individuals or groups representing the general population. In our baseline estimates, we separately consider the daily number of violent events and demonstrations observed in each country. 23 acled is updated on a daily basis, but events are added retrospectively if they did not yet appear in the various sources immediately after they occur.

24 Though they account for a smaller share of the observations (17.8%), acled also reports information on "Strategic developments", events which are not directly conflictual. These events typically include "pivotal events within campaigns of political violence", such as peace agreements, non-violent transfer of territory, arrests, etc. We do not account for non-violent events in this paper.

demonstrations at the same period in the previous year; in the first half of April 2020, it is more than 50% lower than in the first half of April 2019. The drop is however temporary, as by July 2020, demonstrations surge back to their average in 2019. The drop in violent events is less striking, yet they also decline by almost 20% in March-April 2020 compared to the previous year. (internal and international), limitations of public gatherings, and stay-at-home requirements. Measures are ranked on a scale ranging from 0 to 4: 0 means no measure is in place, 1 means that the measure is a recommendation, and 2 to 4 denote mandated measures of different scale or intensity. 26 The OxCGRT data also contain information on whether the measure is a national or a regional one.

We pursue two strategies to measure Covid-19 restriction policies. As our baseline, we compute a global index which includes all policies and define a "shutdown" as the period during which this index exceeds some threshold value of restriction intensity. In addition to it, we consider each policy separately in our estimations. The first strategy uses an aggregate index, which is essentially a replication of the "stringency index" computed in OxCGRT data, with the only difference that we consider only nation-wide measures, and ignore regional policies. Our stringency index thus takes the following form:

stringency index it = 1 8 8 p=1 p it max p it (1)
such that each policy p it is weighted by its maximum value for each country i at day t. The stringency index ranges from 0 (no policy implemented) to 1 (all policies implemented at their highest restriction level). We define a binary restriction measure, henceforth called shutdown, which switches to 1 when the stringency index exceeds a certain threshold. In choosing the threshold we face a trade-off, which is apparent in Figure A1.2 (online appendix). The curves represent the share of countries under lockdown, starting from the lowest cutoff value at the top (0.1), down to the highest values at the bottom (0.9). Given that countries tend to start with a package of measures, very low cutoff values make little sense, as they are very correlated with higher values at the start of the shutdown; at the same time, low threshold values imply that countries remain in the "shutdown" state even when most measures have been lifted. For very high cutoff values (0.9), on the other hand, shutdown are very uncommon and short-lasting. We select 0.6 as our baseline cutoff, because it is approximately the threshold of stringency at which the majority of restriction policies are implemented,27 and because this threshold level allows us to retain enough sample variation. However, this choice being partly arbitrary, we also perform several sensitivity exercises. First, we show results obtained with alternative thresholds, within the [0.4; 0.8] interval. Second, we estimate the effect of each of the eight restriction policies separately.

According to our baseline definition, 112 countries in the sample enforced a shutdown between March 6

and September 1 (see online appendix Table A1.2 for the list of starting dates by countries). On the other hand, 22 countries do not impose a shutdown, i.e. in their case the stringency index remains below 0.6 during the entire period. Shutdown lasts for 79 days on average, but there is a large heterogeneity across countries, with a standard deviation of 58 days and a maximum of 170 days for two countries (Paraguay and Honduras). Since implementing restriction policies, countries have not monotonically increased the severity of restrictions over time. Around one-fifth of the countries in the sample have implemented multiple waves of shutdowns (up to three waves). 28 To account for this pattern, we define day 1 to be the day when a shutdown first occurs, and consider days when the stringency index declines below our defined cutoff like an absence of a shutdown. Post-shutdown periods are excluded from our baseline sample. and Montalvo and Reynal-Querol (2005). 29 Fractionalization reflects the probability that two randomly selected individuals from a given country will not share a certain characteristic. Polarization capture the extent to individuals in a country are distributed across different groups. A high polarization index means that there is a large minority in a country. 30 Both variables can capture the relationship between ethnic cleavages and political instability or conflict that could exist across countries (Esteban and Ray, 1994, 1999; Montalvo and Reynal-Querol, 2005). We measure democracy using the combined Polity/Freedom House index as available from the Quality of Government dataset (Teorell et al., 2020). Finally, global institutional quality is proxied by a measure of the rule of law from the Worldwide Governance Indicators (World Bank Group et al., 2010), again retrieved from Quality of Government dataset. This variable captures the confidence in the rules of society by including perceptions on crime, the judiciary system and enforceability.

Since the beginning of Covid-19 pandemic, Reporters Without Borders has been documenting state censorship, disinformation, and negative consequences on the right to reliable news. 31 These effects are argued to be more prominent in countries where media independence and pluralism or respect for freedom of press was rather low before the pandemic. 32 North Korea is a glaring example of how the Reporters Without Borders's evaluation of pre-Covid press freedom across countries correlates with media reporting during the pandemic. The country, which is ranked at the bottom of the 2020 World Press Freedom Index, is yet to report a coronavirus case a year since the disease first emerged. 33 To account for potential bias in the reporting of conflict that could be due to media restrictions, we include the press freedom index from Reporters Without Borders (Quality of Government dataset). 34 Again, we consider the pre-sample average of press freedom to avoid reverse causality concerns.

Descriptive statistics.

Table 1 provides summary statistics for the main variables (Table A1.3 in online 29 Data is available on the authors' personal websites, url.

30 When comparing the fractionalization index with the polarization index, the latter takes into consideration the relative size of each group as a weight, while the size of each group has no effect on the former.

31 A real time update of Covid-19 related violations are compiled here.

32 Reporters Without Borders use anecdotal evidence in the 2020 World Press Freedom Index to highlight a correlation between press freedom violations related to the coronavirus epidemic and the ranking in the Index, url.

33 "North Korea Has Adopted Severe Measures to Stave Off the Coronavirus", Carnegie Endowment for International Peace (December 17, 2020), url. The World Press Freedom index measures the countries' press freedom record in the previous year, url. 34 The press freedom index measures countries on a scale of 0-100, with 100 representing countries with the least press freedom. We inverse the measure, a higher score indicating greater press freedom, to ease interpretation. appendix gives the full list of variables and their summary statistics). The two measures of conflict events that are reported in our sample period display similar daily averages and standard deviation. Our measures of shutdown, with a cutoff at 0.6 or 0.7 for the stringency index, are also relatively similar. Given that acled primarily focuses on developing countries, unsurprisingly, the countries included in our sample exhibit lower GDP per capita (about 6,650 current USD, compared to a world average of 15,000 over the same period), quality of government score (0.44, as compared with a cross-country average of 0.53 at the world level), rule of law indexes (-0.54, while the world level is -0.08) compared to the world average. On the other hand, the level of ethnic heterogeneity is more comparable to the world average (0.54/0.54 in our sample versus 0.51/0.44 at the world level, for polarization and fractionalization respectively). Religious polarization and fractionalization, on the other hand, are both higher in our sample than for the world average (0.62/0.37 in our sample vs. 0.47/0.28 for the global average).

Empirical strategy

Baseline equation. We use an event-study design to examine whether the time path of estimated effect on conflict changes discretely in response to the restriction policies. This allows us to demonstrate if there are any pre-existing trends in conflict intensity propensity across countries that implemented the restriction policies, compared to the non-implementing countries. The absence of pre-trends would rule out a spurious relationship between restriction policies and conflict outcomes. Further, the event-study design enables us to test whether the impact of restriction policies on conflict may evolve over time. We regress conflict outcomes on a set of restriction indicators ranging from 120 days before to 120 days after implementation of the restriction policies, controlling for country and year × month fixed effects, as well as country-specific linear time trends. The latter relax the common trend assumption and capture potential correlated trends in conflicts, Covid-19 outbreak and restriction policies. We further include a set of Covid outbreak dummies denoting the days since the first Covid-19 case has been recorded in the country, aiming to control for any behavioral change among the conflict actors that could be in response to the disease outbreak. 35 Our specification takes the following form:

Conflict it = 120 k=-120 β k Shutdown i,t-k + ∞ k=0 γ k Covid i,t-k + µ ym + η i × T ym + ε it , ( 2
)
where Conflict it is either the number of violent events or the number of demonstrations in country i at day t. Shutdown Finally, note that in these estimations we exclude the post-restriction periods, i.e. the periods during the restrictions are lifted.

Since our dependent variable is the count of conflict events, the baseline model is estimated using a Poisson pseudo maximum likelihood estimator (PPML). The estimation technique is preferable to log-linearized models that are estimated with OLS, as their estimates can be biased under heteroskedasticity (Silva and Tenreyro, 2006). Further, the PPML method provides a natural way to deal with zero values of the dependent variable. We also replicate the baseline analysis with OLS for comparison. Finally, standard errors are clustered at the country level to permit valid inference if errors are auto-correlated within country. To illustrate the impact of restriction policies more concisely and to increase the precision of the estimates, we also consider a corresponding specification with monthly time periods, i.e. where we replace the daily shutdown dummies by a set of months dummies capturing the number of months before and since the start of the restriction (within a four month window around the start of the event).

Threats to identification. The validity of the difference-in-differences (DD) strategy relies on the assumption that countries having implemented shutdown policies are similar to the non-implementing countries. The dynamics of Covid-19 pandemic across countries and how people behaved makes likely that the assumption is violated (Goodman-Bacon and Marcus, 2020). Further, countries have implemented a number of policy measures in response to the pandemic, which makes comparison in terms of the policy treatment difficult (Goodman-Bacon and Marcus, 2020). To address the first concern, we implement a flexible event study design, where we compare the pre-shutdown conflict trends between the treatment and the control groups. In addition, we control for the timing of Covid-19 outbreak to eliminate a likely spurious negative effect of the shutdown measures, since conflict activity could also scale down in response to the disease outbreak. The inclusion of country specific linear time trends also accounts for the possibility that different trends in initial country characteristics, such as in terms of GDP or population density, could have jointly affected Covid-19 dynamics and the conflict outcomes. Finally, we address concern regarding the comparability of shutdown policies in a robustness check where we perform the event study analysis around specific shutdown measures.

Despite the inclusion of various controls for Covid-19 outbreak and country-specific trends, our results remain subject to caution. Specifically, we cannot fully rule out the possibility that the duration of restriction policies is influenced by conflict patterns in the aftermath of the policies implementation. In particular, countries may respond to a surge in conflict by lifting restrictions: it would imply that we are more likely to observe long-lasting policies in countries where the increase in conflict is limited. Consequently, our estimates would represent a lower bound of the true effect. To get an idea of the magnitude of this bias, we estimate equation ( 2) on a sub-sample of countries for which our shutdown measure equals 1 for at least three consecutive months. As shown later, our results do not accord well with the presence of such reverse causality bias. On top of that, one can argue that a similar downward bias would occur if restrictions negatively affect the reporting of conflict events. Taking seriously this potential threat to our identification, we include in our baseline estimations interactions terms between the policies dummies and an indicator of press and media freedom -the assumption being that media reporting is more negatively impacted in countries where freedom of press was low before the pandemic -which is consistent with the anecdotal evidence discussed earlier. Note that both the policy endogeneity and the reporting problems should bias our estimates downwards: hence, the fact that we identify little decline in conflicts that involve organized armed groups or states is already informative.

The impact of country-characteristics. We also allow the response of conflict to restriction policies to differ along the line of country characteristics. First, we split the sample according to country characteristics that, in light of the theories developed in Section 2, could affect how violence responds to such policiesethnic or religious divisions, income, democracy level in particular. We then include interactions between our policy restriction indexes and dummies denoting high (above median) or low (below median) levels of a given country characteristics. The specification takes the form:

Conflict it = 4 m=-4 Shutdown i,t-m (β H k C H i + β L k C L i ) + ∞ k=0 γ k Covid i,t-k + µ ym C H i + µ ym C L i + η i T ym + ε it , (3)
We consider the monthly decomposition of the effect of policies in these estimations, mostly because the noise associated with the daily one is magnified when using such a sample split. In Equation (3), we control for time dummies interacted with high/low country characteristics dummies, so that β H k and β L k can be interpreted as the deviation of a country belonging to the high/low group to its average conflict level, due to the restriction policy. Finally, note that, when considering country characteristics other than income, we also systematically control for interaction terms between restriction policies and real GDP per capita, as most of our country indicators may correlate with income.

Results

Demonstrations

Baseline estimates. Figure 2 displays the main dynamic estimates of the impact of policy restrictions on the number of demonstrations in a country, i.e. both protests and riots. The points denote the daily estimates ( βk , with k ∈ [-120, ..., 120]), with dotted lines representing 90% confidence intervals. The red boxes depict the monthly estimates and their confidence intervals. The number of events start declining around a week before the policies are implemented, and are estimated to drop on average by 0.8 event per day during the first month. The decline in the number of events just prior to Day 0 is likely due to the fact the our measure is defined around the stringency level of restrictions rather than simply when any restriction measure was first imposed. 36 The decline in demonstrations is substantial, when we compare to the unconditional mean of 1.5 events per day observed in our sample.

The impact of shutdown policies on demonstrations is short-lived: after a month, the number of demonstrations is back to their pre-crisis level, and remain around that level in the following months. Overall, on average, our results suggest that Covid-related policy restrictions only lead to a temporary drop in demonstrations, and then, after a month, there is a noticeable resurgence of demonstration activity. This U-shaped response is reinforced in our sensitivity analysis. First, using different thresholds to define a country-specific shutdown (Figures A3.5 and A3.7) leads to similar results. Second, the results are strikingly similar across regions 36 Alternatively, the pre-shutdown decline could be due to anticipation of the restrictions: however, looking at the measures individually (Figures A6.16.(a) to A6.16.(f) in the online appendix) we find that, with few exceptions, the decline in demonstrations is statistically significant only after measures are implemented. This suggests that the observed pre-shutdown decline found in Figure 2 mostly comes from the fact that some measures are already in place before our shutdown measure switches to 1. Note: This figure plots the coefficients β k of equation 2 when conflict represents the daily number of demonstrations in a country. Shutdown i,t-k is an indicator that equals 1 since when the Stringency index is equal or above a cutoff of 0.6 (range between 0-1), in a given country. The points denote the daily estimates, with dotted lines representing 90% confidence intervals. The red boxes depict the monthly estimates and their confidence intervals. All specifications include an indicator variable that equals 1 if as of day t country i had confirmed the first Covid-19 case t -k days ago, year-month fixed effects, country fixed-effects and country-specific linear time trends. Standard errors in parentheses are clustered at the country-level. Table A1.3 in the online appendix contains descriptive statistics about each variable used in the estimation.

(online appendix Figures A7.18.(a) for Africa, A7.18.(c) for Asia, A7.18.(e) for Latin America), whether we use an OLS estimator instead of PPML (Figure A4.9), remove countries with multiple waves of shutdown (Figure A5.13), or if we estimate the effect of each policy separately (Figure A6.15).37 Similarly, we do not observe any substantial differences across countries with different socio-economic or institutional characteristics: the same short-lived decline in demonstrations is found regardless of the country's level of income, ethnic or religious divisions, or institutional quality (online appendix Figures A9.22 Several mechanisms could in principle explain these results. First, this temporary drop in demonstrations may be spurious, i.e. either caused by media reporting of the events being hampered in the short-run, or by countries actually relaxing the mobility or social distancing constraints over time. We consider these two explanations as unlikely. First, controlling in these estimations for a full set of interaction terms between the policy implementation dummies and a measure of initial country-specific media freedom leaves the results largely unchanged (online appendix Figure A2.3). Second, when restricting the sample to countries where the shutdown lasted for at least three months -i.e. countries that maintained the restriction for a longer time period -we find similar results (online appendix Figure A5.11).

Two non-exclusive explanations remain. The more natural explanation is that policy restrictions increased coordination and mobilization costs, but that this increase was quickly counteracted by the negative consequences of the policies -unemployment, economic deprivation -which pushed demonstrations back to their pre-restrictions level. Alternatively, in the early stage of the pandemic, individuals may have interpreted restriction policies as a signal of potential health risks, before eventually realizing that such risks were (from an individual perspective) lower than expected. Such a mechanism would also explain why the drop is only temporary (even in the absence of economic deprivation), and would be consistent with the fact that the size of the temporary decline does not appear to depend on the strength of policy restrictions (Figure A3.7), or on ex-ante country characteristics. We however consider both interpretations as equally plausible at this stage; properly identifying the most relevant channel would require more detailed data.

Violent Events

Figure 3 depicts the effect of Covid-related restrictions on violent events -battles, violence against civilians, remote violence -in a similar way as in the previous figure. The results differ sharply from those on demonstrations: we do not observe an instantaneous reduction in violent events. If anything we find that the number of events, on average, slightly increases following the implementation of the measures: though the effect is imprecisely estimated, estimates for month t + 4 are statistically different from the pre-implementation period, and the average post-implementation coefficient is significantly higher than the pre-implementation average. A similar lack of decline is observed when using a linear estimator (Figure A4.10) or by removing countries that imposes multiple shutdown periods (Figure A5.14). On the other hand, using a higher threshold for the stringency at 0.7 leads to a sharper estimated increase in conflict (Figure A3.6). In fact, increases in the intensity of violent events is only found for cutoffs of stringency indexes of 0.5 and above (Figure A3.8), and the sharpest increase is found for cutoffs of 0.6 or above. Similarly, restricting the sample policy-implementing countries to those in which restrictions lasted at least three months also points to a stronger conflict-inducing effect of these measures (Figure A5.12). This last result suggests that our estimates do not suffer from a downward bias created by the potential lifting of restrictions in countries where they lead to an increase in violent conflicts.

The increase in mobility and coordination costs due to the policy restrictions do not appear to cause a drastic reduction in events that involve armed actors, yet, this average effect masks a significant heterogeneity. In subsequent analysis, we address some of the potential sources of heterogeneity.

Heterogeneity across policies. We first estimate whether our results could be driven by specific restriction policies. The estimated results when we consider each policy separately are shown in Figure 4 (Figure A6.17 Note: This figure plots the coefficients β H k (in red) and β L k (in blue) of equation 3 when conflict represents the daily number of violent events in a country. Shutdown i,t-k is an indicator that equals 1 since when the Stringency index is equal or above a cutoff of 0.6 (range between 0-1), in a given country. The specification controls for time dummies interacted with high/low GDP per capita dummies (high C H i versus low C L i ). The points denote the monthly estimates, with dotted lines representing 90% confidence intervals. The specification includes an indicator variable that equals 1 if as of day t country i had confirmed the first Covid-19 case t -k days ago, year-month fixed effects, country fixed-effects and country-specific linear time trends. Standard errors in parentheses are clustered at the country-level. Table A1.3 in the online appendix contains descriptive statistics about each variable used in the estimation.

the roots of conflict are already present. 38 First, the rise in violent events is more pronounced in poorer countries, which could be due to different operating mechanisms (Figure 5, and robustness Figure A9.25 in the online appendix). By aggravating poverty, the pandemic may have reduced the opportunity cost of violence (Becker, 1968; Grossman, 1991; Dal Bó and Dal Bó, 2011) or impeded the state capacity to fight against armed opposition (Berman et al., 2011, Fearon and Laitin, 2003). The latter channel is especially unique to the pandemic as states have diverted immense resources to contain the spread of Covid-19. Keeping poverty level constant, violence may also increase because a peaceful resolution of the conflict becomes more difficult, particularly because the negative shock to state revenues may create commitment problems.

Second, we find that the effect is more conspicuous in more authoritarian countries (Figure 6 Note: This figure plots the coefficients β H k (in red) and β L k (in blue) of equation 3 when conflict represents the daily number of violent events in a country. Shutdown i,t-k is an indicator that equals 1 since when the Stringency index is equal or above a cutoff of 0.6 (range between 0-1), in a given country. The specification controls for time dummies interacted with high/low country characteristics dummies (high C H i versus low C L i ). The points denote the monthly estimates, with dotted lines representing 90% confidence intervals. All specifications control for interaction between restriction policies and real GDP per capita, and include an indicator variable that equals 1 if as of day t country i had confirmed the first Covid-19 case t -k days ago, year-month fixed effects, country fixed-effects and country-specific linear time trends. Standard errors in parentheses are clustered at the country-level. Table A1.3 in the online appendix contains descriptive statistics about each variable used in the estimation.

countries. 39 Little changes in violence is observed for other categories. The results are more mixed in the case of religious divisions (Figure 6.(d)): though violence displays a slight increase for highly polarized countries, the estimates are not statistically significant. The problem here is that the correlation between religious polarization and fractionalization is extremely high (0.94 in our sample), which may prevent us from disentangling the effect of each variable. Indeed, when estimating the impact of fractionalization (online appendix Figure A9.24.(a)) or polarization alone (online appendix Figure A9.24.(b)), we find a similar pattern in both cases: increase in countries with high levels, a stagnation in low level countries. Overall, these various results and robustness exercises (Figures A9.25 and A9.26 in the online appendix) suggest that ethnic and religious cleavages play an important role in shaping the impact of Covid restriction policies 39 Ideally, we would like to include four categories in these estimations: high polarization, low polarization, high and low fractionalization. However, given the large number of fixed effects and the presence of country specific trends, collinearity prevents us from estimating the "low fractionalization" category. The opposite trends in conflict activity in ethnically highly "polarized" and "fractionalized" countries is consistent with evidence that measures of polarization and fractionalization tend to run in opposite directions in explaining conflict behavior (Esteban and Ray, 2008). The opposite trend in conflict activity is less pronounced for countries with high religious polarization and fractionalization, which is likely due to the fact that religious polarization and fractionalization measures are highly correlated. on violent conflict. Indeed, both ethnic and religious tensions may have been amplified by the restriction policies. The escalation in violence could be due to scapegoating of minorities that gets heightened during epidemics (Voigtländer and Voth, 2012; Jedwab et al., 2019). 40 Overall, we can summarize the results of this last section as follows: (i) restriction policies had little peace-inducing effect on violent events, which if anything, increased in some countries when restrictions have been enforced; (ii) the most vulnerable countries are those where the antecedents for disputes are already present, i.e. poor, socially divided countries, and those with authoritarian regimes. In these countries, violent events increased the most, either because Covid restrictions exacerbated pre-existing tensions, or because they made peaceful resolutions of ongoing disputes more difficult to reach.

Conclusion

In this paper, we provide real-time evidence of how enforcing restrictions to limit the spread of coronavirus affects conflicts globally. First, we observe a sharp decline in demonstrations, that involve spontaneous acts of public protests or rioting, following the imposition of restriction policies. But the reduction is short-lived, as the number of demonstrations are back to their pre-restriction levels in the second month, and remain there in the subsequent periods. Second, we observe that the purported increase in mobilization or coordination costs, following the imposition of Covid-19 restrictions, has a negligible impact on violent events that involve organized armed groups. However, the effect is significantly larger for countries which exhibit an initial fertile ground for conflicts, namely countries with high-poverty, ethno-religious strife or non-democratic institutions Our work is only a first step to try to understand how Covid-related policies might impact conflict. Given the preliminary nature of the data, and the relative short time span currently available, more work is surely needed. Many important dimensions of the conflict-covid nexus are not considered in our analysis. For instance, future research could try to further explore cross-country heterogeneity in conflict responses, and consider within-country characteristics, such as urbanization and local income levels. Given the current collapse in many commodity markets, how natural resources rich regions react to the spread of the virus is surely an important question to study as well. 40 Jedwab et al. (2019) find that Black Death mortality increased Jewish persecution, while Voigtländer and Voth (2012) show that Black Death pogroms created anti-Jewish sentiment that persisted over centuries.

Figure 1 .

 1 Figure 1.(a) displays the weekly number of events since January 1, 2019. The total number of demonstrations declines dramatically from March 2020 onward. In March 2020, it is 16.5% lower than the number of 21 'Maduro's Grip on the System is now Total.' Venezuela's Opposition Faces Uncertain Future After Parliamentary Elections, Time (December 7, 2020, url). 22 These data have been widely used in recent conflict literature, see for instance Besley and Reynal-Querol (2014), Michalopoulos and Papaioannou (2016), and Berman et al. (2017).23 acled is updated on a daily basis, but events are added retrospectively if they did not yet appear in the various sources immediately after they occur.24 Though they account for a smaller share of the observations (17.8%), acled also reports information on "Strategic developments", events which are not directly conflictual. These events typically include "pivotal events within campaigns of political violence", such as peace agreements, non-violent transfer of territory, arrests, etc. We do not account for non-violent events in this paper.

Figure 1 :

 1 Figure 1: Evolution of conflict events and Covid-19-related Policies

  Covid-19-related Policies Source: Authors' computation from ACLED and OxGRT data. See main text for details. Covid-19-related Policies. Information on the various governmental policies in response to the Covid-19 outbreak are collected from the Oxford Covid-19 Government Response Tracker (OxCGRT)(Hale et al., 2020).25 OxCGRT systematically assembles information on several policy responses governments have implemented, using public sources such as official government press releases and newspaper articles. Data include information on 18 indicators gathered under four categories: containment and closure policies, economic policies, health system policies and miscellaneous policies. In this paper, we focus on Covid-19 related policy responses under the OxCGRT category "containment and closure policies". This categories include eight specific policies: the closings of school, workplaces and public transport, travel restrictions

Figure 1 .

 1 Figure 1.(b) depicts the global move toward restriction measures in response to the Covid-19 crisis. Until early March, none of the countries in our sample had imposed a shutdown, based on the cutoff of 0.6 for the

Figure

  Figure 2: Timing of Shutdown and Demonstrations

  to A9.23(a)-(d)).

  .(a) to FigureA6.17.(h) show the detailed results with confidence intervals and daily estimates).

Figure 3 :

 3 Figure 3: Timing of Shutdown and Violent Events

  .(b) and robustness Figure A9.26.(b) in the online appendix). This result is in line with anecdotal evidence that authoritarian regimes or leaders have used emergency powers acquired during the pandemic to repress political opposition (Coyne and Yatsyshina, 2020). Third, Figure 6.(c) show that the increase in violent events is stronger for more ethnically polarized 38 Similar results are obtained in online appendix Figures A9.26 when we use the alternative stringency threshold to define the shutdown binary.

Figure

  Figure 6: Country characteristics: violent events

Table 1 :

 1 Descriptive Statistics

	Obs. Mean S.D. Min Max

Note: Source: authors' computation from ACLED, QoG,

OxCGRT and Reynal-Querol (2002)

data. See main text for more details.

  i,t-k denote the set of indicator variables capturing each day around the implementation

of a shutdown policy at time t. Covid i,t-k is an indicator variable that equals 1 if as of day t country i had confirmed the first Covid case (t -k) days ago. µ ym are year-month fixed effects, capturing common year-month shocks, in particular the global spread of Covid-19 that correlates with lockdown policies, and worldwide seasonality in conflict incidence. η i are country fixed effects accounting for any time-invariant or slow-moving country characteristics, such as political system, institutions, or culture, that may affect conflict, Covid outbreak and restriction policies. Finally, η i × T ym are country-specific linear time trends that allow for the unobserved country-specific conflict propensities to trend linearly over time. β k are the coefficients of interest, which identify the variations in conflict intensity around the implementation of restriction policies.

One of the consequences of the current slowdown in economic activity is a collapse of the market for commodities, from agricultural to oil and mineral prices. Such drop of commodity prices may have multiple effects on conflict. Studying such effects is beyond the scope of this paper, in which we focus on the specific impact of Covid-19 related shutdown and lockdown policies.

A resurgence in public protests following Covid-19 restrictions have been reported in various countries such as Israel, Spain, Britian and Hong Kong. See: The pandemic is an era of protests -and protest restrictions, Washington Post (October 2, 2020, url).

Given the time-span of our empirical exercise, we concentrate here on channels which may plausibly have short-term consequences for conflict risk. As Rohner (2020) points out, the current Covid-19 crisis and associated policies also have a number of long term implications, through their effect on education or international cooperation.

Data were downloaded on September 12, 2020.

For instance, in the case of closure of schools, a value of 2 implies a required measure to close some part of the schooling system (only high schools or only public schools), while a value of 3 implies a complete shutdown of the schools at all levels.

If five out of eight policies are fully implemented, the index equals 0.625.

In the sensitivity analysis, we replicate our baseline results by removing countries with multiple shutdown periods. Results are largely unchanged (FigureA5.13 for demonstrations and FigureA5.14 for violent events).

For instance[START_REF] Farboodi | Internal and external effects of social distancing in a pandemic[END_REF] suggest that forward looking and rational actors would internalize the cost of getting sick. They find evidence that individuals in the United States significantly reduced their social activity even before the state and the local governments imposed the restriction policies.

The effect is comparable in size and duration across all policies, except for restrictions to international movements which exhibit a much smaller and statistically insignificant decline.

* This work was supported by French National Research Agency Grants ANR-17-EURE-0020. Mathieu Couttenier acknowledges financial support from the IDEXLYON, University of Lyon (French National Research Agency, "Programme Investissements d'Avenir" ANR-16-IDEX-0005) and financial support from the French National Research Agency ANR-20-COV4-0005-01. Nathalie Monnet acknowledges financial support from the Swiss National Research Foundation (grant Economics of Conflict and Violence P0GEP1-175125 and grant Land Concentration and Rural Poverty, 100018/178902)). Rohit Ticku acknowledges financial support from the Institute for the Study of Religion, Economics and Society, Chapman University.

Conflict intensity (β hat ) (+/-1.64 SE )

-120 -90 -60 -30 0 30 60 90 120 Days Note: This figure plots the coefficients β k of equation 2 when conflict represents the daily number of violent events in a country. Shutdown i,t-k is an indicator that equals 1 since when the Stringency index is equal or above a cutoff of 0.6 (range between 0-1), in a given country. The points denote the daily estimates, with dotted lines representing 90% confidence intervals. The red boxes depict the monthly estimates and their confidence intervals. All specifications include an indicator variable that equals 1 if as of day t country i had confirmed the first Covid-19 case t -k days ago, year-month fixed effects, country fixed-effects and country-specific linear time trends. Standard errors in parentheses are clustered at the country-level. Table A1.3 in the online appendix contains descriptive statistics about each variable used in the estimation.

Shelter-in-place and restrictions to internal movements are the two policies that have the most significant explanatory power. These measures are arguably among the most stringent restrictions in the set of policies that we consider. The other types of restrictions appear to have little effect on the number of violent events. Types of events. We next utilize the richness of the acled dataset by focusing on the sub-events categories among violent events. We observe a significant increase in battles months after the implementation (Figure A8.19), and to a lesser extent on the violence against civilians (Figure A8.21). These results hint towards potential bargaining failures such as reduced opportunities for conflict mediation and a lower cost of repression "when the world is not watching" (Durante and Zhuravskaya, 2018). We however do not detect any significant effect on remote violence. These are types of violent events which "aim at creating asymmetrical conflict dynamics by preventing the target from responding" and include various tactics of explosions (bombs, drone strikes, chemical weapons, suicide bombing, etc.) (Raleigh et al., 2010). It is plausible that Covid-related restrictions have affected access to conflict-specific capital technologies (such as explosives or advanced weapons). In that sense, restriction policies could also change the nature of violent conflict by affecting fighting technologies. Note: This figure plots the coefficients β k of equation 2 when conflict represents the daily number of violent events in a country. Shutdown i,t-k is an indicator that equals 1 since when each policy separately takes the value 2 or above in a given country. Each line denotes the daily estimates for a specific policy. All specifications include an indicator variable that equals 1 if as of day t country i had confirmed the first Covid-19 case t -k days ago, year-month fixed effects, country fixed-effects and country-specific linear time trends. Standard errors in parentheses are clustered at the country-level. Table A1.3 in the online appendix contains descriptive statistics about each variable used in the estimation.

Country characteristics. As a preliminary evidence on how the effect of restriction policies on violent

events could be different across countries, we allow our estimate to vary by continent. While we observe little impact of restrictions in Latin America, violent events are found to increase in Asia and Africa, the impact being more delayed but also stronger in the latter case (online appendix Figures A7.18.(b) for Africa, A7.18.(d) for Asia, A7.18.(f) for Latin America).

We explore the argument further by allowing heterogeneity across country-specific characteristics, and by splitting the sample across different dimensions that are motivated by the theoretical discussion: i) pre-period real GDP per capita (Figure 5); ii) pre-period institutional quality (rule of law and democracy scores) . Polarization and fractionalization measures capture the relationship between ethnic and religious cleavages and political instability or conflict that could exist within countries (Esteban and Ray, 1994, 1999; Montalvo and Reynal-Querol, 2005). Note that we include polarization and fractionalization measures jointly to account for their correlation. We return to this specific point below. Finally, with the exception of the results on income, the estimates are obtained after controlling for the effect of GDP per capita. The visual inspection of our results delivers three interesting features, that are globally consistent with our second prediction: Covid-19 restrictions are more likely to exacerbate violence in countries where