Marginalization and contemporaneous aggregation in multivariate GARCH processes

Time Series;GARCH Models

Unobserved Component Time Series Models with ARCH Disturbances

We are also grateful to Neil Shephard, Mervyn King, Sushil Wadhwani, Manuel Arellano, Herman van Dijk, Rob Engle, and several anonymous referees for their comments. In addition we would like to thank Ray Chou. Frank Diebold, and Charles Goodharl for supplying us with the data used in the applicalions. The second author acknowledges financial support from the Basque Government; the third author acknowledges support from the LSE Financial Markets Group and the Spanish Ministry of Educalion and Science.Publicad

Monetary Policy, Bank Bailouts and the Sovereign-Bank Risk Nexus in the Euro Area

The paper analyses the empirical relationship between bank risk and sovereign credit risk in the euro area. Using structural VAR with daily financial markets data for 2003-13, the analysis confirms two-way causality between shocks to sovereign risk and bank risk, with the former being overall more important in explaining bank risk, than vice versa. The paper focuses specifically on the impact of non-standard monetary policy measures by the European Central Bank and on the effects of bank bailout policies by national governments. Testing specific hypotheses formulated in the literature, we find that bank bailout policies have reduced solvency risk in the banking sector mostly at the expense of raising the credit risk of sovereigns. By contrast, monetary policy was in most, but not all cases effective in lowering credit risk among both sovereigns and banks. Finally, we find spillover effects in particular from sovereigns in the euro area periphery to the core countries

Managing technological uncertainty in science incubation:A prospective sensemaking perspective

This paper focuses on the adaption challenge that confronts the top management team (TMT) of science incubators in situations of substantial technological uncertainty. To do that, we draw on the three-year longitudinal analysis of a major bioscience catalyst in the UK. Through the lens of ‘prospective sensemaking’, we follow the TMT as they work with stakeholders in their ecosystem to make sense of a significant technological shift: the convergence of life sciences, IT and other sciences in the health care environment. Our analysis reveals how prospective sensemaking resulted in the launch of a new strategy to exploit these emerging opportunities. However, stakeholders’ increasingly fragmented interpretation of the term convergence and the anticipation of legitimacy challenges in the wider ecosystem resulted in the repositioning of the incubator. Our findings contribute to extant research on science incubation. In particular, the paper sheds light on the complex interactions of incubator TMT’s with stakeholders in situations of technological change and uncertainty. Moreover, responding to technological change does not only affect the structural conditions of an incubator. Rather, it may also require changes to the positioning of the incubator in order to maintain legitimacy in the wider ecosystem. The paper also suggests managerial as well as policy level implications

Testing for Identification in SVAR-GARCH Models: Reconsidering the Impact of Monetary Shocks on Exchange Rates

Changes in residual volatility in vector autoregressive (VAR) models can be used for identifying structural shocks in a structural VAR analysis. Testable conditions are given for full identification for the case where the volatility changes can be modelled by a multivariate GARCH process. Formal statistical tests are presented for identification and their small sample properties are investigated via a Monte Carlo study. The tests are applied to investigate the validity of the identification conditions in a study of the effects of U.S. monetary policy on exchange rates. It is found that the data do not support full identification in most of the models considered, and the implied problems for the interpretation of the results are discussed

Credit Supply: Identifying Balance-Sheet Channels with Loan Applications and Granted Loans

To identify credit availability we analyze the extensive and intensive margins of lending with loan applications and all loans granted in Spain. We find that during the period analyzed both worse economic and tighter monetary conditions reduce loan granting, especially to firms or from banks with lower capital or liquidity ratios. Moreover, responding to applications for the same loan, weak banks are less likely to grant the loan. Our results suggest that firms cannot offset the resultant credit restriction by turning to other banks. Importantly the bank-lending channel is notably stronger when we account for unobserved time-varying firm heterogeneity in loan demand and quality

Structural Vector Autoregressions: Checking Identifying Long-Run Restrictions via Heteroskedasticity

Long-run restrictions have been used extensively for identifying structural shocks in vector autoregressive (VAR) analysis. Such restrictions are typically just-identifying but can be checked by utilizing changes in volatility. This paper reviews and contrasts the volatility models that have been used for this purpose. Three main approaches have been used, exogenously generated changes in the unconditional residual covariance matrix, changing volatility modelled by a Markov switching mechanism and multivariate generalized autoregressive conditional heteroskedasticity (GARCH) models. Using changes in volatility for checking long-run identifying restrictions in structural VAR analysis is illustrated by reconsidering models for identifying fundamental components of stock prices