HyperText Corpus Initiative : how to help researchers sieving the web? Proposal for the "Using

Since its foundation in May 2009, the médialab Sciences Po1 works to foster the use of digital methods and tools in social sciences. With the help of existing tools and methods, we experienced the use of web mining techniques to extract data on collective phenomena. We also attended the symposiums organised by the two institutions responsible of web archiving in France: BnF2 and INA 3 where we learnt about the difficulties posed to social scientists by the use of web archives. Actually our own experience in mining the live web wasn't easier. Such difficulties, we believe, can be explained by the lack of tools allowing scholars to build themselves the highly specialized corpora they need from the wide heterogeneity of the web. The web isn't a well-known document space for scholars or librarians. Its hyperlinked and heterogeneous nature requires to envision new ways of conceiving and building web corpora. And this notion of web corpus is a necessity for both live and archived web. If methods are not appropriate enough for analysing the live web, the problem will not be easier on an archive where the time dimension adds complexity.

In order to cope with this problem, we decided to launch an initiative joining the forces of actors coming from web archiving, web mining, social sciences and librarians communities. Our proposal is to set a coherent chain of tools to build, preserve and analyse web corpora. We aim at integrating existing pieces of software into a common methodological chain addressed at Social scientist and librarians needs. For this reason an important feature of this project is that it explicitly refuses to address huge corpora and targets. On the contrary, it focuses on topic-centric corpora in the order of a thousand nodes.

Thus the Hypertext Corpus Initiative4 (HCI) has been founded in a kickoff workshop organised in October 2010 at the médialab Sciences Po gathering researchers, librarians and developers5 . HCI working groups met several times in late 2010 to address the numerous issues our ambition has to face :

What is a website?

When one provides a researcher one of the existing web mapping tools, a question popsup inevitably: what is a website? This question is far from being naïve. It comes from the difficulty encountered to map topic objects (actors, issues...) on URLs. Indeed to analyse the web, the web pages have to be grouped in coherent sets, defined by a common portion of their URLs. The standard way to group pages is by domain name: http://www.domain.tld . But this way of grouping pages hides the heterogeneity of the web, as some websites are structured in subdomains or subfolders. Hence, grouping web pages by domain name is often irrelevant (blogs in a platform, profiles in a social network, papers in a press website...). To address these concerns, we defined the concept of web entity. Our point is that web entities have to be defined by the user, based on what he considers a relevant set of web pages. The web entities are the basic aggregation level of web pages, the one on the top of which all other activities (like tagging, crawling, analysis, archiving…) will be based.

Control the corpus on a topic

The tools for building a web corpus currently at the disposal of social scientists (navicrawler6 and issuecrawler7 ) impose a binary choice between manual and automatic approach. On one hand, the navicrawler is a brilliant tool to build a corpus out of a personal browsing experience. Even if this is the most accurate way of building a corpus, researchers were quickly discouraged by the amount of time this method requires. On the other hand, the online crawler issuecrawler (developed by the Digital Methods Initiative) is a perfect tool to expand a small list of URLs by automatically and remotely crawling them. However, the researchers feel they lost control on the corpus building process by discharging it to an automatic tool. Finally neither manual nor automatic methods suit the need. It's like having to choose between tweezers and a caterpillar to find a needle in a haystack. Thus we propose to develop a research driven crawling method, able to let the researcher control the crawl process. As we experienced, although automatic crawling is definitely necessary to harvest the outbounding links of a web entity, it's not suitable for extending the corpus. An automatic crawler should not be in charge of deciding which new web resources are to be included in or excluded from the corpus. This decision needs a qualitative analysis by the researcher. First to decide whether or not each new web resource fits the research intention but also to define the shape of the web entity to be associated to this resource. For those reasons, we aim at developing a method of research driven crawling. A researcher should first define the granularity of his/her web entities, then decide to crawl them but with a depth-only crawling (i.e. crawling at null distance). While performing its crawling activities, the system should report new URLs back to the user asking him/her to create web entities from them. We believe that the researcher should analysethe results after each iteration of crawl to drive the automatic harvest by a qualitative analysis. A few quantitative indicators could be provided to guide the researcher in his/her decision making process. These are the very same indicators used for automatic filtering between iteration like co-link analysis or focus crawling, but used this time as a base for a manual decision.

Web corpus are not static maps

Due to the lack of integration of tools around a common notion of web corpus (at least in social sciences), the work results to static maps of websites. It's already a meaningful results but just the skin of what we could achieve.

First, the time dimension is missing. Here the collaboration with web archivists (BnF, INA and perhaps IIPC) is a key to foreseen the integration of archiving mechanism on the basis of the web corpus. Secondly, corpus are outdated the minute they are built. Hosting a web corpus at the center of a series of tools let us imagine a way to frequently crawl the corpus not only to archive the selected web entities but also to detect new web resources as candidates to be included in the corpus. This process would then propose this new entry to the researcher who could decide to include it in or exclude it from the corpus. Finally the notion of corpus will allow contents indexation and extraction to overtake the only topological analyses.

Explore to handle

To analyse web corpora we use an exploratory data analysis tool based on network visualisation (namely Gephi8 ). This is a perfect way to represent the nature and composition of the web. But why should we wait the end of the work to finally have exploration means at hands? We strongly believe that exploratory data analysis (EDA) could help researchers to handle the complexity of web corpora all along the process: seeing a map evolving during a crawl, using data visualisation to reflect quantitative indicators such as indegrees or terms frequencies, seeing clusters of web entities to understand the composition of the corpus… An important aim of our project is therefore to integrate such EDA tools in every step of the chain from the corpus building to the analysis. Those tools could be based on existing technologies, such as Gephi or processing9 , applied to the corpus of web entities created by researchers.

Following those principles, HCI develops a prototype called Hyphen. We hope this work will help fostering the use of web corpora in Social Sciences and thus the use of web archives by researchers. The first beta version is to be released in 2011.

http://medialab.sciences-po.fr

http://www.bnf.fr/documents/cp_memoire_web_sites_electoraux.pdf

http://atelier-dlweb.fr/blog/

http://jiminy.medialab.sciences-po.fr/hci

from INA, BnF, Digital Methods Initiative Amsterdam, Density Design Lab Milano, Linkfluence, TIC migration research group, the Gephi consortium, Webatlas association, Sciences Po library and ISC PIF

http://webatlas.fr/wp/navicrawler/

https://www.issuecrawler.net/ Out of the Box conference May 9, 2011 -proposal for the « Using Web Archives » panel -Paul Girard

http://www.gephi.org

http://www.processing.org


Jérôme Creel
email: jerome.creel@sciencespo.fr

Paul Hubert
email: paul.hubert@sciencespo.fr

Mathilde Viennot
email: mathilde.viennot@ens-cachan.fr.

Assessing the Interest Rate and Bank Lending Channels of ECB Monetary Policies *

Keywords: Transmission Channels, Unconventional Monetary Policy, Pass-through. JEL codes: E51, E58

This paper assesses the transmission of ECB monetary policies, conventional and unconventional, to both interest rates and lending volumes for the money market, sovereign bonds at 6-month, 5-year and 10-year horizons, loans inferior and superior to 1M€ to non-financial corporations, cash and housing loans to households, and deposits, during the financial crisis and in the four largest economies of the Euro Area. We first identify two series of ECB policy shocks at the euro area aggregated level and then include them in country-specific structural VAR. The main result is that only the pass-through from the ECB rate to interest rates has been really effective, consistently with the existing literature, while the transmission mechanism of the ECB rate to volumes and of quantitative easing (QE) operations to interest rates and volumes has been null or uneven over this sample. One argument to explain the differentiated passthrough of ECB monetary policies is that the successful pass-through from the ECB rate to interest rates, which materialized as a huge decrease in interest rates during the sample period, had a negative effect on the supply side of loans, and offset itself its potential positive effects on lending volumes.

Introduction

This paper aims at establishing the effect of conventional and unconventional ECB monetary policies on both interest rates and lending volumes in the four largest economies of the Eurozone during the global financial crisis. This issue is topical since Mario Draghi, chairman of the ECB, justified the latest unconventional policy tool -the Outright Monetary Transactions -by the disruption of the ECB monetary policy transmission to the real economy in some Eurozone countries.

Most of the literature has focused on the transmission during the financial crisis of ECB monetary policies through the interest rate channel. We contribute to this literature in three ways. First, we assess at the same time interest rate and bank lending channels using interest rates and lending volumes for new loans. Second, we investigate the effects of both conventional and unconventional monetary policies and disentangle the effect of one from the other. In the spirit of [START_REF] Bachmann | Confidence and the transmission of government spending shocks[END_REF], we artificially shutoff the effects of the quantitative easing (QE) policy when analysing the effects of the conventional one, and vice-versa. Third, the analysis is performed, over the financial crisis sample, for the four largest economies of the Eurozone: Germany, France, Italy and Spain, and at a disaggregated level encompassing money markets, sovereign bonds at 6-month, 5-year and 10-year horizons, loans inferior and superior to 1M€ to non-financial corporations, cash and housing loans to households, and deposits.

We proceed in two steps. We first identify two series of ECB policy shocks at the euro area aggregated level and orthogonal to various macroeconomic indicators. Second, we include these two estimated series of interest rate and QE policy shocks in country-specific structural VARs with 4 additional endogenous variables, namely industrial production, inflation, and interest rates and lending volumes for each market considered, as well as oil prices, a composite indicator of systemic stress (CISS) and the Euro Stoxx 50 index as exogenous variables. We impose both short-run and long-run restrictions when we artificially shut off either the effect of conventional or unconventional policies. We also use panel data estimation to control for country fixed-effects, potentially important in the policy transmission to lending markets.

The main result is that only the pass-through from the ECB rate to interest rates has been really effective, consistently with the existing literature, while the transmission mechanism of the ECB rate to volumes and of QE operations to interest rates and volumes has been null or uneven over this sample. QE operations have some sparse effects on interest rates but overall, their pass-through to credit conditions seems to be extremely weak.

One argument to explain the differentiated pass-through of ECB monetary policies is that the successful pass-through from the ECB rate to interest rates, which materialized as a huge decrease in interest rates during the sample period, had a negative effect on the supply side of loans, and offset itself its positive effects on lending volumes. The interest rate channel may be a substitute to the bank lending channel on the supply side when net interest margins deteriorate, and ever more so for larger banks which retain market power. More precisely, if banks have positive net interest-sensitive positions, lowering the central bank interest rate will lower their profitability. If average returns affect banks' marginal decisions, this will reduce net lending, (partially) offsetting the positive stimulus stemming from the interest rate reduction. [START_REF] Landier | Banks' Exposure to Interest Rate Risk and The Transmission of Monetary Policy[END_REF] show that a 100 basis point decrease in the Fed funds rate leads a US bank at the 75th percentile of the income gap distribution to decrease lending by about 1.6 percentage point annually relative to a bank at the 25th percentile.

One policy implication of this result would be for central banks to target more directly non-financial corporations or households when implementing unconventional monetary policy or to constrain more effectively bank lending to ensure an operative pass-through to non-financial corporations or households.

The rest of the paper is organized as follows. Section 2 presents the related literature, section 3 the theoretical framework, section 4 data and section 5 the empirical strategy and results. Section 6 concludes.

Related Literature

One of the pioneering studies about the monetary transmission mechanism is [START_REF] Bernanke | The Federal Funds Rate and the Channels of Monetary Transmission[END_REF] showing that the Fed funds rate records perfectly the variations of the central bank reserves; the transmission mechanism can thus be assessed through the impact of a change in this rate on retail rates (the interest rate channel) and on volumes of loans and bank deposits (the bank lending and money channels). The articulation of these two channels matters because loans supply hinges on the speed and size of the pass-through from policy interest rates to money market rates and bank interest rates. The pass-through from the central bank interest rate to commercial bank interest rates is expected to be positive, whereas the pass-through to lending and deposits volumes is expected to be negative because of the arbitrage with bonds. Their results highlight a positive pass-through to lending and deposit rates while banking volumes do not react.

Before the recent financial crisis, many studies have focused on the transmission mechanism in the Eurozone and have highlighted its heterogeneity. First, regarding the interest rate channel, many econometric methods have been used to estimate the pass-through between the central bank interest rate, money market rates and bank interest rates. Donnay and [START_REF] Degryse | Bank Lending Rate Pass-Through and Differences in Transmission of a Single EMU Monetary Policy[END_REF] used a SVAR to investigate the pass-through from money market rates to several bank lending rates and government bond rates in 12 European countries; they highlighted the role played by the banking sector in the transmission process of monetary policy to the real economy via the interest rate channel. De Bondt (2005) used a vector errorcorrection model to examine the interest rate pass-through at the euro area level, focusing on the passthrough of the overnight interest rate to longer term market interest rates and retail bank interest rates; the pass-through is found incomplete on the money market and lagged on the retail banking market. [START_REF] Sorensen | Bank interest rate pass-through in the Euro area: a cross-country comparison[END_REF] conducted a cross-country analysis of the pass-through between market interest rates and bank interest rates; using the panel unit root method and cointegration tests, the article shows a large heterogeneity between euro area countries. Sander and [START_REF] Kleimeier | Expected versus unexpected monetary policy impulses and interest rate pass-through in euro-zone retail banking markets[END_REF] focused on the nature of the conventional monetary policy tools and their impact on the interest rate channel, differentiating between expected and unexpected monetary policy impulses. They showed how important was the kind of monetary policy for the speed and completeness of the pass-through and have paved the way for a new branch of literature studying the impact of several monetary policy tools on money market rates and retail bank interest rates. The literature on the bank lending channel is less numerous than the one on the interest rate channel; [START_REF] Chatelain | Monetary Policy Transmission in the Euro area: New Evidence from Micro Data on Firms and Banks[END_REF] brought evidence of a credit channel in the Eurosystem: bank balance sheet characteristics play a role in the lending reaction to monetary policy impulses, as banks that have a less liquid asset composition reduce lending by more in response to a restrictive monetary policy action than more liquid banks do; this lends support to the hypothesis that banks draw on their liquid assets to cushion the effects of monetary policy on their loan portfolio. Last, De Santis and Surico (2013) analyse in the four largest economies of the Euro Area the effect of monetary policy on bank lending according to bank characteristics.

Regarding our sample period, many articles have studied whether the worldwide financial crisis has affected the interest and credit channels of conventional monetary policy in the Eurozone1 . Most of these studies focus on the interest rate channel. [START_REF] Andries | La crise financière a-t-elle affecté la transmission de la politique monétaire sur les prêts aux sociétés non financières dans les pays de la zone euro ?[END_REF] used ARDL models and cointegration methods to assess the impact of the financial crisis on the transmission mechanism to nonfinancial corporations' lending rates, while [START_REF] Blot | Business lending rate pass-through in the Eurozone: monetary policy transmission before and after the financial crash[END_REF] uses a SUR-ECM model to estimate the effect of the financial crisis on the global pass-through between market rates and bank interest rates. Both articles showed that the financial crisis has clogged up the transmission mechanism, especially for long-term rates. [START_REF] Belke | Interest Rate Pass-Through in the EMU: New Evidence from Nonlinear Cointegration Techniques for Fully Harmonized Data[END_REF] conducted a cross-country analysis of the pass-through since the crisis in 12 countries of the European Monetary Union and allowed for nonlinear patterns for short-run dynamics of loan rates. [START_REF] Aristei | Interest Rate Pass-Through in the Euro Area during the Financial Crisis: a Multivariate Regime-Switching Approach[END_REF] studied the interest rate channel in five distinct markets (money market, government debt market, lending market to non-financial corporations, lending market to households, deposit market); using a Markov-Switching vector autoregressive model, they found a reduction of the pass-through during the crisis, especially in the lending market to non-financial corporations. [START_REF] Gigineishvili | Determinants of Interest Rate Pass-Through: Do Macroeconomic Conditions and Financial Market Structure Matter?[END_REF] examined the financial structure as a possible cause of heterogeneity that exists within the various monetary transmission mechanisms worldwide, even within the Eurozone; macroeconomic determinants such as per capita GDP, inflation or market volatility and financial market structure variables such as exchange rate flexibility, credit quality or overhead costs affect the interest rate pass-through. Last, [START_REF] Panagopoulos | Monetary and banking policy transmission through interest rates: an empirical application to the USA, Canada, the UK and the Eurozone[END_REF] compare the interest rate channels during the turmoil in the Eurozone and other comparable regions (USA, UK, Canada), while [START_REF] Karagiannis | Interest rate pass-through in Europe and the US: Monetary policy after the financial crisis[END_REF] compare the interest rate transmission mechanism in the Eurozone to the US and provides policy suggestions to reinforce the effectiveness of monetary policy in hard times.

During the financial crisis, implementing monetary policy became much more complex as the transmission mechanism has been severely impaired by disruptions in the financial markets; as a consequence, the ECB resorted to unconventional measures to provide additional stimulus to the economy. The literature assessing the effectiveness of such measures is large for the US2 , while it is not very abundant regarding the Eurozone yet. About the interest rate channels of unconventional tools, [START_REF] Cordemans | Central bank rates, market rates and retail bank rates in the euro area in the context of the recent crisis[END_REF] looked at certain unconventional monetary decisions (full liquidity allotment, longer term refinancing operations, covered bond purchases, Securities Market Programme) and their impact on Euro area and Belgium's retail bank interest rates. [START_REF] Abbassi | The effectiveness of monetary policy in steering money market rates during the recent financial crisis[END_REF] analyzed the predictability of money market rates on the basis of monetary policy expectations and the impact of extraordinary central bank measures on money market rates. [START_REF] Gambacorta | The bank lending channel: Lessons from the crisis[END_REF] focused on the bank lending channel during the crisis and measured the short-term impact of monetary policy changes on bank lending; Darracq-Paries and Santis (2013) studied the macroeconomic impact of 3-year long-term refinancing operations (LTRO) via the bank lending channel and the mitigation of liquidity and funding risks. Two papers have kindled our attention by tackling both interest rate and credit channels of monetary transmission: Bonnacorsi di Pati and Sette (2012) studied the transmission of monetary shocks affecting Italian banks' balance sheets to the volume and cost of credit granted to nonfinancial corporations, while [START_REF] Lenza | Monetary policy in exceptional times[END_REF] analyzed the response of the ECB, the Fed and the Bank of England to the financial crisis through non-standard monetary policy measures and their impact on money market spreads and real economy.

The Theoretical Framework

Traditional models used for the analysis of monetary policy usually pay little attention to financial frictions. Under the classical view of the transmission channel, interest rates impact economic activity by affecting relative prices in the economy (relative prices of capital, of future consumption in terms of current consumption and of domestic goods in terms of foreign goods); this constitutes the interest channel and encompasses most mechanisms that are not associated with financial frictions. The interest channel is economically significant because of the link between changes in short nominal rates and long real interest rates. 3To the extent that consumer and investment spending, and in the first place, durable/capital goods expenditure depends on long rather than short rates, the expectations theory of the term structure has to hold, so that short rate movements are transmitted to long rates. Nevertheless, many features of the configuration of interest rates during the financial crises are puzzling from the perspective of the expectations hypothesis. 4 Furthermore, term premia have affected the extent to which changes in short rates are translated into further changes along the yield curve by responding systematically to offset movements in short rates, which is expected to weaken the effect of policy changes.

On the other hand, the bank lending channel explains the effects of monetary policy with movements in the supply of bank credit. The essential feature is that the central bank can affect credit supply by financial intermediaries by altering the quantity of base money, which affects the banks' balance sheet (see Equation 1):

= - 1 L(r,i,y) λ( r , i )D( τ ) (1)
where L(r, i, y) represents the demand for loans, which depends negatively on the interest rate on loans r and positively on the interest rate on bonds i and on GNP y (which captures the transactions demand for credit). λ(r,i) represents the rate of return on the available assets, D bank's deposits and τ the rate of minimum reserves. The monetary policy transmission through this channel may be incomplete thanks to limited liability, credit rationing, or the imperfect substitutability between retail deposits and wholesale deposits or debt on the liability side of banks' balance sheets. [START_REF] Bernanke | Credit, Money and Aggregate Demand[END_REF] assume fixed costs of direct financial market participation and banks' incomplete/imperfect information in the market for equity and corporate debt. They show that such structures amplify the effects of monetary policy shocks. However, this amplification will depend on the size of the lending contraction for a given shock: the more interest inelastic is the demand for money; the lower will be this contraction. Moreover, this amplification can be reversed if i) the difference in income elasticities of the demand function for money and loans exceeds a threshold, ii) the differences in absolute elasticities of loan supply and loan demand with respect to the two interest rates (r and i) exceed some thresholds or iii) the interest elasticity of the money multiplier is too large, which might have been the case during the recent financial crisis.

Table 1 summarizes the theoretically-expected effective credit and interest rate channels. In the context of the global financial crisis, the pass-throughs may have vanished partly, compared to their values in normal times.

Data

This paper focuses on the monetary transmission mechanism since the global financial crisis. Our dataset goes from June 2007 to December 2012 with a monthly frequency so comprising 67 observations. The monetary transmission mechanism is assessed for conventional and non-conventional tools and through five distinct markets: the money market, the sovereign debt market, the lending market to non-financial corporations, the lending market to households and the deposit market. 6 For each country (France, Germany, Italy and Spain), the endogenous variables needed for estimating the monetary transmission mechanism include the specific interest rates and their corresponding volumes.

First, interest rate and lending channels are assessed in the money market. For money market rates, we use the euro area overnight rates (EONIA) over the period. As they are mostly made at the overnight maturity, interbank loans are chosen to be the corresponding volumes 7 ; they are related, for each country, to the stock of loans from domestic monetary and financial institutions to other Euro area's monetary and financial institutions (MFI 8 ). These data were available over the period in national MFIs balance sheets (Banque de France, Banco de España, Banca d'Italia, Bundesbank). These interbank loans are expressed in month over month percentage change.

The monetary transmission mechanism is then assessed in the sovereign debt market. Data are available in auctions results of the corresponding countries, on national debt agencies' websites (Agence France Trésor, Banco de España, Banca d'Italia, Deutsche Finanzagentur). After compiling all auctions, we have chosen allotments and corresponding yields for bonds with 6 month, 5 year and 10 year maturity. Indeed, these maturities seem to be the most representative of monthly auction amounts 9 . These For each country, bonds from 165-day to 210-day maturity are chosen as a proxy for 6-month maturity bonds, bonds from 54-month to 72-month maturity for 5-year maturity bonds and bonds from 114-month to 132-month maturity for 10-year maturity bonds; thus, we escape the problem of disregarding close-to-reference maturity issuances (5 months and 27 days instead of 6 months for example). The allotments are expressed 6 See appendix for data descriptions and descriptive statistics. 7 Most interbank loans are for maturities of one week or less, the majority being overnight (80%) -see [START_REF] Michaud | What drives interbank rates ? Evidence from the Libor panel[END_REF]. 8 MFIs (Monetary and Financial Institutions) include the central bank, credit institutions resident in the domestic country and other resident MFIs such as Money Market Funds. 9 Together, they represent 43% of the French sovereign debt (18% for 6-month maturity bonds, 13% for 5-year maturity bonds and 13% for 10-year bonds), 85% of the Spanish one (5% for 6-month, 38% for 5-year, 42% for 10-year), 59% of the Italian one (33% for 6month, 13% for 5-year and 14% for 10-year), 34% of Germany's (13% for 6-month, 10% for 5-year and 11% for 10-year).

in percentage of euro area GDP. Last, three dummy variables (6 months, 5 years, 10 years) are used to indicate whether the country has issued bonds with the corresponding maturity over the period or not.

In order to compute the interest rate and credit channels on the market of loans to domestic non-financial corporations over the period, we take the new business volumes and their corresponding annual interest rates for loans with an amount up to 1 million € and for loans over this amount; new business volumes are then expressed as a percentage of Euro area GDP. These data were available over the period on national central bank's databases (Banque de France, Banca d'Italia, Bundesbank) or Datastream for Spain.

The lending market to households is decomposed between housing loans and cash loans. For each country, we took the new business volume of housing loans and cash loans and their corresponding annual interest rates. New business volumes are expressed as a percentage of Euro area GDP. These data were available over the period on national central bank's databases (Banque de France, Banca d'Italia) or Datastream for Spain and Germany.

Last, we have three sets of volumes and corresponding rates for the deposits market.

Disentangling the Effects of Conventional and Unconventional Policies

Identifying the ECB policy shocks

Before estimating country-specific structural VAR, we first identify two series of ECB policy shocks at the euro area aggregated level and orthogonal to a wide array of macroeconomic indicators. The rationale for this step is that ECB policies are decided and executed at the aggregate level for the whole euro area. We estimate the following two equations with euro area aggregated data. (3)

From equations ( 2) and (3), we assume that the residuals ηrate,t and ηQE,t are the series of aggregated policy shocks implemented by the ECB. We then introduce these two series in the country-specific structural VAR, which enable us to derive ECB policy shocks that are exogenous to country-specific macroeconomic developments.

The Structural VAR Model

A

αβ = = + ++ ∑ p t i t-i t t i1 Z Z Xe (4)
The reduced-form errors comprise the contemporaneous effects of each variable on the others and combine the exogenous innovation of a given variable to the contemporaneous responses to the other variables. The recursive identification assumption postulates that the structural errors are independent, and the identification of exogenous innovations relates reduced-form errors and structural errors through a lower triangular matrix. This means that the covariance between the reduced-form errors is attributed to the structural error of the variable ordered previously in Zt, and that the structural error is uncorrelated to the reduced-form errors of the preceding variables. The recursive identification assumption therefore depends on the ordering of the variables in the vector Zt.

In our benchmark VAR, we assume that shifts in industrial production and inflation result in a contemporaneous change in both policy variables, and prices and volumes on each credit market. The latter two also react contemporaneously to policy variables, while by construction policy variables would react to innovations to credit prices and volumes only with a lag. Concerning the relative position of the two policy variables, we assume that the QE interventions react with a lag to the ECB interest rate consistently with the prevalence of the conventional instrument over unconventional ones.

The structural VAR analysis is performed with 3 lags and with a small sample estimator because the number of observations is small. The variance-covariance matrix is estimated with a small-sample degrees-of-freedom adjustment: the small-sample divisor used is 1/(T-m) instead of the maximum likelihood divisor 1/T, T being the sample size and m the average number of parameters in each of the equations. We checked the eigenvalue stability condition of the VAR model to interpret impulse-response functions. All the eigenvalues lie inside the unit circle, so our VAR model satisfies the stability condition.

In Figure 1, we plot the Euro Area aggregated policy shocks estimated in section 5.1. and the country-and market-specific shocks estimated with equation (4) but including ECB and QE raw variables in Zt in order to provide comparisons between both possibilities for identifying policy shocks. Discrepancies between country-and market-specific shocks support the choice of identifying aggregate policy shocks.

Shutting-off one of the two policy variables

In order to disentangle the effect of conventional and unconventional policies, we artificially shut-off the effect of one of the two policy variables by imposing restrictions on its coefficients in both equations for determining prices and volumes of each credit market. We then isolate the effect of the other policy variables on credit prices and volumes. A necessary condition for credit prices and volumes not to react to policy variables at any horizon is that policy variables are ordered before credit prices and volumes in Zt so that they do not react on impact. This condition plus restricting to zero the coefficients on lagged policy variables in equations for credit prices and volumes to zero is sufficient for imposing that credit prices and volumes do not react to one of the two policy variables at any horizon. These restrictions are implemented by estimating the VAR model using seemingly unrelated regressions.

Estimates

Figure 2 plots the impulse response in interest rates to a one-S.D. innovation (a 0.10 percentage point increase) in the ECB interest rate, for Germany, France, Italy and Spain (rows) and for the money market, sovereign bonds at 6-month, 5-year and 10-year horizons, loans inferior and superior to 1M€ to nonfinancial corporations, cash and housing loans to households, and deposits. We expect a positive response of interest rates to the ECB interest rate. The pass-through is indeed significant and positive as expected for most of the countries and markets, except for German and French sovereign bond markets and loans to households.

Figure 3 plots the impulse response in credit volumes to a one-S.D. innovation in the ECB interest rate. We expect credit volumes to be negatively correlated to an increase in the ECB interest rate and positively for deposit volumes. Evidence rather points that there is no clear-cut pass-through over the considered sample from the ECB rate to volumes, except for money markets in Spain, loans to non-financial corporations in Italy and Spain, cash loans to households, housing loans to households in Italy and Spain, and deposits in France and Italy.

Figure 4 presents the impulse response in interest rates to a one-S.D. innovation (a 0.25 percentage point increase of Euro Area GDP) in QE operations. We expect that quantitative easing interventions have a negative effect on interest rates since increasing the money supply. There is no evidence of this passthrough from QE to interest rates over our sample, except for sovereign bonds at the 6-month horizon and for Spain at the 5-year horizon.

Figure 5 plots the impulse response in lending volumes to a one-S.D. innovation in QE operations. We expect that quantitative easing interventions have a positive effect on credit volumes for the same reason than previously: they should increase money supply. Once again, there is no evidence of the expected pass-through from QE to lending volumes, except for money markets in France and Spain, for loans superior to 1M€ to non-financial corporations in France, and for deposits in Germany.

Panel Data Robustness

In order to assess the robustness of previous results, we estimate the equivalent empirical model (Equation 4) with explanatory variables considered contemporaneously except for the lagged endogenous variable. We also introduce directly the ECB and QE series rather than shocks identified in 5.1 as the panel estimation is performed at the aggregated level rather than at the country level. This also enables to assess the sensitivity of our results to our identification of shocks. The set-up is not dynamic, but underlines immediate static effects; is univariate rather than multivariate, and country variables are grouped together rather than analysed separately using time series methods. This enables to control for country fixedeffects, potentially important in the transmission of monetary policy to credit markets. Moreover, the forthcoming results are independent of the identification hypotheses of the structural VAR scheme.

Hausman tests indicated that the individual effects and our explanatory variables were systematically related, so that the fixed effects estimator (FE, also called within estimator) was the most appropriate choice. The FE estimator, which allows for varying intercept terms across countries, deals efficiently with unobserved heterogeneity, as time-invariant omitted variables do not bias the regression results. This proves especially important when unobservable variables, such as financial markets and banking industry characteristics, and regulatory rules and institutions, may be important in the transmission of monetary policy. An FE estimator has the advantage of controlling for different national effects of stable unobserved variables, and over our short sample, we may assume those unobservable variables are stable. The appropriateness of our FE estimation was also confirmed by an F-test for the significance of fixed effects. Likewise, the Wooldridge test for autocorrelation in panel data indicated a first order correlation. We therefore selected the FE estimator robust to an AR(1) disturbance term because it addresses all the statistical issues of our sample, including links between individual effects and explanatory variables, and auto-correlation.

Table 3 plots estimates of the variables affecting lending interest rates and volumes for the money market, sovereign bonds at 6-month, 5-year and 10-year horizons, loans inferior and superior to 1M€ to nonfinancial corporations, cash and housing loans to households, and deposits. It confirms the previous results that only the pass-through from the ECB rate to interest rates has been really effective (except for sovereign bond markets and cash loans to households), while the transmission mechanism of the ECB rate to volumes and of QE operations to interest rates and volumes has been null or uneven.

Table 4 provides estimates of the effect of the ECB rate and QE operations on lending interest rates and volumes for Germany and France on the one hand, and Italy and Spain on the other hand. We use a dummy, labelled "South", which equals 1 for Italian and Spanish observations and interact it with ECB and QE variables. The interaction term captures the difference between the two effects, the one for northern countries and the one for southern countries. The effect for Germany and France is simply the coefficient of ECB and QE variables, while the effect for Italy and Spain is the sum of the interaction coefficient and the coefficient for ECB and QE variables. In general, monetary policy transmission is similar between northern and southern countries. However, it appears that the respective pass-throughs from the ECB rate to 6-month-horizon sovereign bond interest rates, to housing loans to households and to deposits have been higher for Italy and Spain than for "northern countries". Such is also the case for the pass-through from QE to 5-year-horizon sovereign bond volumes.

Concluding Remarks

This paper assesses the transmission of ECB monetary policies, conventional and unconventional, to both interest rates and lending volumes for the money market, sovereign bonds at 6-month, 5-year and 10-year horizons, loans inferior and superior to 1M€ to non-financial corporations, cash and housing loans to households, and deposits, during the financial crisis and in the four largest economies of the Euro Area.

The main result is that only the pass-through from the ECB rate to interest rates has been really effective, consistently with the existing literature, while the transmission mechanism of the ECB rate to volumes and of QE operations to interest rates and volumes has been null or uneven over this sample. One argument to explain the differentiated pass-through of ECB monetary policies is that the successful passthrough from the ECB rate to interest rates, which materialized as a huge decrease in interest rates during the sample period, had a negative effect on the supply side of loans, and offset itself its positive effects on lending volumes. Exceptions to this appear on markets where very specific actions have been taken by the ECB, namely sovereign-bond markets at 5-year horizon in southern countries.

Figure 1: Comparing Euro Area aggregated policy shocks with country-and market-specific shocks

Note: Thick lines plot the Euro Area aggregated policy shocks estimated in section 5.1. while thin lines plot the countryand market-specific shocks estimated with equation ( 4) but including ECB and QE raw variables in the vector of endogenous variables Zt (not the aggregated policy shocks estimated previously as done in section 5.2.). Since the analysis is performed for 4 countries and 9 markets, there are 36 series of country-and market-specific shocks plotted.

Figure 2 :

 2 Figure 2: Impulse Response Functions of interest rates to a positive ECB interest rate shock in Germany (1 st row), France (2 nd ), Italy (3 rd ) & Spain (4 th )

Figure 3 :

 3 Figure 3: Impulse Response Functions of volumes to a positive ECB interest rate shock in Germany (1 st row), France (2 nd ), Italy (3 rd ) & Spain (4 th )

Figure 4 :

 4 Figure 4: Impulse Response Functions of interest rates to a positive QE shock in Germany (1 st row), France (2 nd ), Italy (3 rd ) & Spain (4 th )

Figure 5 :

 5 Figure 5: Impulse Response Functions of volumes to a positive QE shock in Germany (1 st row), France (2 nd ), Italy (3 rd ) & Spain (4 th )

Table 1 -

 1 Expected effects of monetary policy shocks 5

		Conventional policy	Unconventional policy
	INTEREST RATES
	-Money market rates	+	-
	-Government bond rates	+	-
	-Lending rates to NFC	+	-
	-Lending rates to households	+	-
	-Deposit rates	+	-
	CREDIT VOLUMES
	-Money market volumes	-	+
	-Government bond volumes	-	+
	-Lending volumes to NFC	-	+
	-Lending volumes to households	-	+
	-Deposit volumes	+	+

Table 2 :

 2 5 markets decomposed in 9 submarkets.

	Money market rates	Money market volumes	1d (overnight)
	Government bond rates	Government bond volumes	6m -5y -10y
	Lending rates to NFC loans	Lending volumes to NFC	inf1M -sup1M
	Lending rates to households	Lending volumes to households	cash -housing
	Deposit rates	Deposit volumes	1d (overnight)

Conventional monetary policy is assessed through the ECB rate for main refinancing operations, whose data over the period are available from the ECB database. The amount of securities held for monetary purposes, as described in the ECB's weekly financial statements, and including Securities Market Program, 1 st and 2 d Covered Bond Purchase Programs amounts are used to measure non-conventional policies since the beginning of the financial crisis. For robustness tests, we use the amount of long-term refinancing operations and the size of the European Central Bank's balance sheet as well. These data are all available in ECB Statistical Data Warehouse, and are expressed as a percentage of Euro area (17 members) GDP.

  For each country, we use the deposit rate to households and non-financial corporations on overnight new business deposits. We use the corresponding deposit stocks that are expressed in month over month percentage change. All these data are available over the period on ECB Statistical Data Warehouse.

Controls include the consumer price index, industrial production, oil prices, CISS and Euro Stoxx 50 indices. For each country, the consumer price index is available on ECB Statistical Data Warehouse, and the volume of industrial production, used as a proxy for domestic output, is available on Eurostat. Both are expressed in year over year percentage change. Oil prices, CISS and Euro Stoxx 50 indices are the same variable for all countries and correspond to Brent crude oil price in euro, expressed in month over month percentage change, to the Composite Indicator for Systemic Stress, capturing financial instability, and to the stock price index for the major 50 European firms. All three are available on ECB Statistical Data Warehouse.

  The number of lags p is equal to 3 and the estimation sample period starts in December 2006 to obtain residuals on the sample period studied: June 2007 -December 2012.

	αα α = = + ∑ p t 0 QE i1 = = α α ++ pp ∑∑ 1,i t-i 2,i t-i CPI IP i1 i1 αα α 3,i Oil + + ++ 4 t 5t 6 t 7t t-i ECB rate Unemp CISS STOXX
	ααη +++ 8 t 9 t Bonds Credit	QE ,t
	ββ ββ = = + ∑ p t 0 1,i ECB rate CPI i1 = = β β ++ pp ∑∑ t-i 2,i t-i IP i1 i1 ++ + + 4 t 5t 6 t QE Unemp CISS	β β 7t 3,i Oil t-i STOXX	(2)
	ββη +++ 8 t 9 t Bonds Credit	rate ,t

  structural VAR model is used to decompose the aggregated ECB interest rate and QE interventions into country-specific mutually orthogonal components with a structural economic interpretation. We augment a standard VAR for monetary policy analysis including industrial production (IP), inflation (CPI) with the two aggregated ECB interest rate (ECB) and QE shocks, new loans' interest rate (*_r) and volumes (*_v) for each market (*) analyzed. We include in the estimation oil prices, the CISS and STOXX as exogenous variables in the vector Xt. Let Zt represent the (k x 1) vector that contains the k endogenous variables at date t. In the benchmark specification, Zt = [IP, CPI, QE, ECB, *_v, *_r]'. The regression of Zt on its own lags p produces the reduced-form VAR errors et:

See appendix for a summary table of the related literature.

See Bernanke, Reinhart and Sack (2004)'s indirect evidence or more recently,Fleming, Hrung and Keane (2008),[START_REF] Hrung | Responses to the Financial Crisis, Treasury Debt, and the Impact on Short-Term Money Markets[END_REF],[START_REF] Krishnamurthy | The effects of quantitative easing on interest rates: channels and implications for policy[END_REF],[START_REF] Thornton | The Effectiveness of Unconventional Monetary Policy: The Term Auction Facility[END_REF],[START_REF] Stroebel | Estimated impact of the Fed's mortgage-backed securities purchase program[END_REF]

Provided that the central bank affect real interest rates, the impact of monetary policy depend on the interest rate sensitivity of aggregate demand and supply, which may explain the decline of the monetary pass-through during the recent financial crisis.

See Gürkaynak and Wright (2012).

A conventional monetary policy shock corresponds to an increase in the policy rate, while an unconventional monetary policy shock corresponds to an expansion of the central bank balance sheet.

* We thank seminar participants at the FESSUD Annual Conference 2013 for helpful conversations and comments. This research project benefited from funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement n°266800 (FESSUD).

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