Vasco M. Carvalho

Bio: Vasco M. Carvalho is an academic researcher from University of Cambridge. The author has contributed to research in topics: Consumption (economics) & Stylized fact. The author has an hindex of 21, co-authored 48 publications receiving 3495 citations. Previous affiliations of Vasco M. Carvalho include The Turing Institute & Barcelona Graduate School of Economics.

The Network Origins of Aggregate Fluctuations

Abstract: This paper argues that in the presence of intersectoral input-output linkages, microeconomic idiosyncratic shocks may lead to aggregate fluctuations. In particular, it shows that, as the economy becomes more disaggregated, the rate at which aggregate volatility decays is determined by the structure of the network capturing such linkages. Our main results provide a characterization of this relationship in terms of the importance of different sectors as suppliers to their immediate customers as well as their role as indirect suppliers to chains of downstream sectors. Such higher-order interconnections capture the possibility of “cascade effects” whereby productivity shocks to a sector propagate not only to its immediate downstream customers, but also indirectly to the rest of the economy. Our results highlight that sizable aggregate volatility is obtained from sectoral idiosyncratic shocks only if there exists significant asymmetry in the roles that sectors play as suppliers to others, and that the “sparseness” of the input-output matrix is unrelated to the nature of aggregate fluctuations.

The Network Origins of Aggregate Fluctuations

Abstract: This paper combines material from Carvalho’s Ph.D. dissertation at the University of Chicago (Carvalho, 2008) and Acemoglu, Ozdaglar, and Tahbaz-Salehi (2010). We thank the editor, Stephen Morris, and four anonymous referees for very helpful remarks and suggestions. We thank Stefana Stantcheva for excellent research assistance and Bill Kerr and Kaushik Ghosh for initial help with the NBER manufacturing productivity database. Carvalho thanks his advisor Lars Hansen and other members of his thesis committee, Robert Lucas and Timothy Conley. We are also grateful to John Fernald, Xavier Gabaix, Ali Jadbabaie, Alp Simsek, Hugo Sonnenschein, Jean Tirole, Jaume Ventura and numerous seminar and conference participants for useful feedback and suggestions. Carvalho acknowledges financial support from the Government of Catalonia (grant 2009SGR1157), the Spanish Ministry of Education and Science (grants Juan de la Cierva, JCI2009-04127, ECO2008-01665 and CSD2006-00016) and Barcelona GSE Research Network. Acemoglu, Ozdaglar and Tahbaz-Salehi acknowledge financial support from the Toulouse Network of Information Technology, National Science Foundation (Grant 0735956) and the Air Force Office of Scientific Research (Grant FA9550-09-1-0420).

Supply Chain Disruptions: Evidence from the Great East Japan Earthquake

Abstract: This paper quantifies the spillover effect of exogenous shocks, such as earthquakes, on other firms through the supply chain network. Combining micro data on inter-firm transaction networks and geographic information systems, we examine firms' sales growth and transaction relationships outside the tsunami-hit areas before and after the Great East Japan Earthquake. We find that sales growth shows a negative but insignificant effect for firms with suppliers in the affected areas and a negative and significant effect for firms with customers in the affected areas. When we focus on exiting firms in the affected areas as the firms from where the spillovers originated, the sales growth of linked firms outside the affected areas exhibits negative and significant effects for both upstream and downstream firms. Furthermore, significantly negative effects on downstream firms are shown for not only directly linked firms but also indirectly linked firms, with two and three degrees of separation. Finally, we find that firms tend to establish new transactions when they have transaction partners in the affected areas.

From micro to macro via production networks

Abstract: Amodern economy is an intricately linked web of specialized production units, each relying on the flow of inputs from their suppliers to produce their own output, which in turn is routed towards other downstream units. In this essay, I argue that the structure of this production network is key in determining whether and how microeconomic shocks—affecting only a particular firm or technology along the chain—propagate throughout the economy and shape aggregate outcomes. Therefore, understanding the structure of this production network can better inform both academics on the origins of aggregate fluctuations and policy makers on how to prepare for and recover from adverse shocks that disrupt these production chains. Two recent events have brought to the forefront the importance of interconnections between firms and sectors in aggregate economic performance. Consider first the 2011 earthquake in Japan. While the triple tragedy of the earthquake, the ensuing tsunami, and the near nuclear meltdown at Fukushima surely resulted in a significant destruction of human and physical capital, its effects would have been largely restricted to the affected areas were it not for the disruption of national

The Great Diversification and its Undoing

Abstract: We investigate the hypothesis that macroeconomic fluctuations are primitively the results of many microeconomic shocks, and show that it has significant explanatory power for the evolution of macroeconomic volatility. We define "fundamental" volatility as the volatility that would arise from an economy made entirely of idiosyncratic microeconomic shocks, occurring primitively at the level of sectors or firms. In its empirical construction, motivated by a simple model, the sales share of different sectors vary over time (in a way we directly measure), while the volatility of those sectors remains constant. We find that fundamental volatility accounts for the swings in macroeconomic volatility in the US and the other major world economies in the past half century. It accounts for the "great moderation" and its undoing. Controlling for our measure of fundamental volatility, there is no break in output volatility. The initial great moderation is due to a decreasing share of manufacturing between 1975 and 1985. The recent rise of macroeconomic volatility is due to the increase of the size of the financial sector. We provide a model to think quantitatively about the large comovement generated by idiosyncratic shocks. As the origin of aggregate shocks can be traced to identifiable microeconomic shocks, we may better understand the origins of aggregate fluctuations.

Forecasting, Structural Time Series Models and the Kalman Filter

Abstract: In this book, Andrew Harvey sets out to provide a unified and comprehensive theory of structural time series models. Unlike the traditional ARIMA models, structural time series models consist explicitly of unobserved components, such as trends and seasonals, which have a direct interpretation. As a result the model selection methodology associated with structural models is much closer to econometric methodology. The link with econometrics is made even closer by the natural way in which the models can be extended to include explanatory variables and to cope with multivariate time series. From the technical point of view, state space models and the Kalman filter play a key role in the statistical treatment of structural time series models. The book includes a detailed treatment of the Kalman filter. This technique was originally developed in control engineering, but is becoming increasingly important in fields such as economics and operations research. This book is concerned primarily with modelling economic and social time series, and with addressing the special problems which the treatment of such series poses. The properties of the models and the methodological techniques used to select them are illustrated with various applications. These range from the modellling of trends and cycles in US macroeconomic time series to to an evaluation of the effects of seat belt legislation in the UK.

An Illustrated User Guide to the World Input-Output Database : the Case of Global Automotive Production

Abstract: This article provides guidance to prudent use of the World Input–Output Database (WIOD) in analyses of international trade. The WIOD contains annual time-series of world input–output tables and factor requirements covering the period from 1995 to 2011. Underlying concepts, construction methods and data sources are introduced, pointing out particular strengths and weaknesses. We illustrate its usefulness by analyzing the geographical and factorial distribution of value added in global automotive production and show increasing fragmentation, both within and across regions. Possible improvements and extensions to the data are discussed.

Capital in the 21st Century

Abstract: On 19 December 2014, the Centre for Economic Policy Research and the Bank of England hosted a discussion forum based around Thomas Piketty’s book, Capital in the twenty-first century, with a number of economists from academia, public sector bodies and private sector institutions. Four speakers presented research on various issues relating to inequality, including: access to education; wealth and taxation policy; and the role of governance and institutions. This article presents each speaker’s key arguments, and includes a summary of the open-floor debate that followed.

Systemic Risk and Stability in Financial Networks

Abstract: We provide a framework for studying the relationship between the financial network architecture and the likelihood of systemic failures due to contagion of counterparty risk. We show that financial contagion exhibits a form of phase transition as interbank connections increase: as long as the magnitude and the number of negative shocks affecting financial institutions are sufficiently small, more "complete" interbank claims enhance the stability of the system. However, beyond a certain point, such interconnections start to serve as a mechanism for propagation of shocks and lead to a more fragile financial system. We also show that, under natural contracting assumptions, financial networks that emerge in equilibrium may be socially inefficient due to the presence of a network externality: even though banks take the effects of their lending, risk-taking and failure on their immediate creditors into account, they do not internalize the consequences of their actions on the rest of the network.

The Network Origins of Aggregate Fluctuations

Abstract: This paper argues that in the presence of intersectoral input-output linkages, microeconomic idiosyncratic shocks may lead to aggregate fluctuations. In particular, it shows that, as the economy becomes more disaggregated, the rate at which aggregate volatility decays is determined by the structure of the network capturing such linkages. Our main results provide a characterization of this relationship in terms of the importance of different sectors as suppliers to their immediate customers as well as their role as indirect suppliers to chains of downstream sectors. Such higher-order interconnections capture the possibility of “cascade effects” whereby productivity shocks to a sector propagate not only to its immediate downstream customers, but also indirectly to the rest of the economy. Our results highlight that sizable aggregate volatility is obtained from sectoral idiosyncratic shocks only if there exists significant asymmetry in the roles that sectors play as suppliers to others, and that the “sparseness” of the input-output matrix is unrelated to the nature of aggregate fluctuations.