Philippe
Martin

Publications in refereed journals 

(Please download and print for personal use only)

•  The effect of COVID certificates on vaccine uptake, health outcomes, and the economy, 2022, Nature Communications, volume 13, Article number: 3942 with Oliu-Barton, Miquel and Pradelski, Bary S. R. and Woloszko, Nicolas (main authors). In the COVID-19 pandemic many countries required COVID certificates, proving vaccination, recovery, or a recent negative test, to access public and private venues. We estimate their effect on vaccine uptake for France, Germany, and Italy using counterfactuals constructed via innovation diffusion theory. The announcement of COVID certificates during summer 2021 were associated – although causality cannot be directly inferred – with increased vaccine uptake in France of 13.0 (95% CI 9.7–14.9) percentage points (p.p.) of the total population until the end of the year, in Germany 6.2 (2.6–6.9) p.p., and in Italy 9.7 (5.4–12.3) p.p. Based on these estimates, an additional 3979 (3453–4298) deaths in France, 1133 (−312–1358) in Germany, and 1331 (502–1794) in Italy were averted; and gross domestic product (GDP) losses of €6.0 (5.9–6.1) billion in France, €1.4 (1.3–1.5) billion in Germany, and €2.1 (2.0–2.2) billion in Italy were prevented. Notably, in France, the application of COVID certificates averted high intensive care unit occupancy levels where prior lockdowns were instated.

• The International Elasticity Puzzle Is Worse Than You Think, with Lionel Fontagné and Gianluca Orefice, 2018, Journal of International Economics.115, 115–129  VOXEU column. Abstract: We instrument export prices with firm level electricity cost shocks and estimate three international price elasticities using firm-level export data: the elasticity of firm exports to export price, tariff and real exchange rate shocks. In standard models these three elasticities should be equal. We find that this is far from being the case. The export price elasticity is the highest, around 5, much larger than the exchange rate elasticity. The international elasticity puzzle is therefore worse than previously thought. We also show that exporters absorb one third of tariff changes in their export prices. Because we take into account this reaction of export prices to tariffs, our estimate of the tariff elasticity corrects from this omitted-variable bias.

• Inspecting the Mechanism: Leverage and the Great Recession in the Eurozone with Thomas Philippon, 2017, American Economic Review, 107(7): 1904–1937.Online Appendix. Column in  VOXEU; Abstract: We provide a comprehensive account of the dynamics of eurozone countries from 2000 to 2012. We analyze private leverage, fiscal policy, labor costs and spreads, and we propose a model and an identification strategy to separate the impact of credit cycles, excessive government spending, and sudden stops. We then ask how eurozone countries would have fared with different policies. We find that countries could have stabilized their employment if they had followed more conservative fiscal policies during the boom. Macro-prudential policies and an early intervention by the ECB to prevent market segmentation and reduce fiscal austerity would also have significantly reduced the recession.

• Are clusters more resilient in crises? Evidence from French Exporters in 2008-2009, with Thierry Mayer and Florian Mayneris, 2016, in Factory-Free Economy, ed. L. Fontagné and A. Harrison, forthcoming Oxford University Press. CEPR Discussion paper 9667. Abstract: We analyze whether firms that agglomerate in clusters and firms that have been selected to benefit from the ``competitiveness cluster'' industrial policy, implemented in France in 2005, have performed better on export markets during the recent economic turmoil. We show that, on average, both agglomeration and the cluster policy are associated with a higher survival probability of firms on export markets, and conditioning on survival, a higher growth rate of their exports. However, these effects are not stronger during the 2008-2009 crisis. This is probably due to the fact that firms in clusters are more dependent on the fate of the ``leader'', i.e.the largest exporter in the cluster.

• "Time to Ship during Financial Crises", with Nicolas Berman, José de Sousa and Thierry Mayer, 2013.  NBER International Seminar on Macroeconomics, University of Chicago Press, vol. 9(1), pages 225 - 260. First draft. NBER WP 18274 and CEPR DP 9089; Abstract: The negative impact of financial crises on trade is magnified for destinations with longer time-to-ship. A simple model shows that exporters react to an increase in the probability of default of importers in destinations in crisis by increasing their export price and decreasing their export volumes. For those with longer shipping time, this is magnified as the default probability increases with time. Some exporters also decide to stop exporting the more so the longer time-to-ship. Using aggregate data (1950-2009) we show that this magnification effect is very robust. We test the firm-level results on French exporter data (1995-2005) and find that they are broadly consistent with our predictions.

•  "Varieties and the transfer problem", 2013, with Giancarlo Corsetti and Paolo Pesenti. Journal of International Economics. Volume 89, Issue 1, Pages 1-12, January 2013 (lead article). Abstract: We revisit the classic transfer problem, accounting for two channels of adjustment: increased trade in existing goods (the intensive margin) and net creation and destruction of product varieties (the extensive margin). Over the medium term, the latter reduces the scope for real exchange rate and terms of trade variability in response to cross-border flows. Simulation exercises based on 2006 data suggest that a transfer of the size of the pre-crisis U.S. current account deficit may require only moderate trend depreciation in real terms, and that the aggregate welfare impact of the transfer is disconnected from the size of the relative price correction.

• "The vulnerability of Sub Saharan Africa to the financial crisis: the case of trade", 2012, with Nicolas Berman , IMF Economic Review 60, 329-364. Abstract: We analyze the effect of past banking crises (1976-2002) on trade with a focus on African exporters. These are particularly vulnerable to a banking crisis in the countries they export to. We distinguish an income effect from a disruption effect. For African exporters the fall in trade (relative to gravity) is around 15 percentage points higher than for other countries in the aftermath of a banking crisis. We analyze several possible causes of this vulnerability.

• "The geography of conflicts and free trade agreements", 2011, with Thierry Mayer and Mathias Thoenig,  American Economic Journal: Macroeconomics, 2012, 4(4): 1–35 (lead article). See The economics and politics of Free Trade Agreements, April 2010, VOX. Abstract: In addition to standard trade gains, regional trade agreements (RTAs) can promote peaceful relations by increasing the opportunity cost of conflicts. Country-pairs with large trade gains from RTAs and a high probability of conflict should be more likely to sign a RTA. Using data from 1950 to 2000, we show that this complementarity between economics and politics determines the geography of RTAs. We disentangle trade gains from political factors by a theory-driven empirical estimation and find that country pairs with higher frequency of past wars are more likely to sign RTAs, the more so the larger the trade gains.

• "How do different exporters react to exchange rate changes?", 2012, with Nicolas Berman and Thierry Mayer, Quarterly Journal of Economics, Volume 127 Issue 1 February 2012. Abstract: We analyze the heterogenous reaction of exporters to real exchange rate changes using a very rich French firm-level dataset with destination-specific export values and volumes on the period 1995-2005. High-performance firms react to a depreciation by increasing more their markup and by increasing less their export volume. This heterogeneity in pricing-to-market is consistent with models where the demand elasticity decreases with firm performance. Since aggregate exports are concentrated on high performance firms heterogenous pricing-to-market may partly explain the weak aggregate impact of exchange rate movements.

• "Public support to clusters: A firm level study of French ``Local productive systems" 2011, with Thierry Mayer and Florian Mayneris, Regional Science and Urban Economics, 41, 108–123. Abstract: We analyze empirically a public policy promoting industrial clusters in France. We use firm-level data on production and employment for firms that benefited from the policy and on firms that did not, both before and after the policy started. The policy selected firms in sectors and regions in relative decline and did not succeed in reversing the relative decline in productivity for the targeted firms. The policy had no robust effect on employment or exports.

• “Spatial Concentration and Firm-Level Productivity in France”, 2011, with Florian Mayneris and Thierry Mayer, Journal of Urban Economics, Volume 69, Issue 2, March 2011, Pages 182-195. Abstract: We analyze the effect of spatial agglomeration of activities on plant-level productivity, using French firm and plant-level data (1996-2004). We exploit short-run variations of variables by making use of GMM estimation. This allows us to control for endogeneity biases that the estimation of agglomeration economies typically encounters. French plants benefit from localization economies and these are relatively well internalized by firms in their location choice: we find very little difference between the geography that would maximize productivity gains in the short-run and the geography actually observed.

• "International portfolios, capital accumulation and foreign assets dynamics", 2010, with Nicolas Coeurdacier and Robert Kollmann, Journal of International Economics, vol 80, 1, p 100-112. Abstract: Despite the liberalization of capital flows among OECD countries, equity home bias remains sizable. The interaction of the following ingredients generates a realistic equity home bias: capital accumulation and international trade in stocks and bonds. In our model, domestic stocks are used to hedge fluctuations in local wage income. Terms of trade risk is hedged using bonds denominated in local and foreign goods. In contrast to related models, the low level of international diversification does not depend on strongly countercyclical terms of trade.

• "The geography of asset trade and the Euro: Insiders and outsiders", 2009, with Nicolas Coeurdacier. Journal of the Japanese and International Economies. Volume 3, issue 2, pages 87-240, June. see column inVOX. Abstract: We find evidence that the euro has implied 1) a unilateral financial liberalization which makes it cheaper for all countries to buy euro zone assets. For bonds and equity holdings, this would translate into approximately 14% and 17% decrease in transaction costs; 2) a preferential financial liberalization which has decreased transaction costs inside the euro zone by approximately 17% and 10% for bonds and equity respectively. 3) a diversion effect that has led euro countries to purchase less equity from outside the euro zone.

• "International portfolios with supply, demand and redistributive shocks" 2009 with Nicolas Coeurdacier and Robert Kollmann,  NBER International Seminar in Macroeconomics. University of Chicago Press. NBER working paper 13424. Abstract: This paper explains three key stylized facts observed in industrialized countries: 1) portfolio holdings are biased towards local equity; 2) they are long in foreign currency assets and short in domestic currency; 3) the depreciation of a country's exchange rate is associated with a net external capital gain. We present a two-country, two-good model with trade in stocks and bonds, and three types of disturbances: shocks to endowments, to the relative demand for home vs. foreign goods, and to the distribution of income between labor and capital. With these shocks, optimal international portfolios are shown to be consistent with the stylized facts.

• "Civil wars and International Trade", with Thierry Mayer and Matthias Thoenig , 2008, Journal of the European Economic Association Papers and Proceedings. April-May, 6 (-3): 541-550.  A  longer version is here in the form of CEPR DP 6659. Abstract: We analyze the relationship between civil wars and international trade.  Trade destruction due to civil wars is very large and persistent. We identify two effects that trade can have on the risk of civil conflicts: it may act as a deterrent if trade gains are put at risk during civil wars but it may also act as an insurance if international trade provides a substitute to internal trade during civil wars. We find support for the presence of these two mechanisms and conclude that trade openness may deter the most severe civil wars (those that destroy the largest amount of trade) but may increase the risk of lower scale conflicts.

• "Make Trade not war?", with Thierry Mayer and Matthias Thoenig.  2008, Review of Economic Studies  Volume 75, 3, 865 - 900 (press coverage: Le Monde, Libération, Enjeux- Les Echos, VoxEU). Data is here. Abstract: We analyse theoretically and empirically the relationship between military conflicts and trade. We show that the conventional wisdom that trade promotes peace is only partially true even in a model where trade is economically beneficial, military conflicts reduce trade, and leaders are rational. When war can occur because of the presence of asymmetric information, the probability of escalation is lower for countries that trade more bilaterally because of the opportunity cost associated with the loss of trade gains. However, countries more open to global trade have a higher probability of war because multilateral trade openness decreases bilateral dependence to any given country and the cost of a bilateral conflict. We test our predictions on a large data set of military conflicts on the 1950–2000 period. We find robust evidence for the contrasting effects of bilateral and multilateral trade openness. Two datasets (available as a zipped files) provide data  needed to replicate results : 1) Gravity regressions; 2) Military conflicts regressions

• "Productivity spillovers, terms of trade and the home market effect", 2007, with Giancarlo Corsetti and Paolo Pesenti,  Journal of International Economics. 73, 99-127. Abstract: This paper analyzes the international transmission and welfare implications of productivity gains and changes in market size when macroeconomic adjustment occurs both along the intensive margin of trade (changes in the relative price of existing varieties of tradable goods) and the extensive margin (creation and destruction of varieties). We draw a distinction between productivity gains that enhance manufacturing efficiency and gains that lower the cost of firms' entry and of product differentiation. Countries with lower manufacturing costs have higher GDP but supply their products at lower international prices. Instead, countries with lower entry costs supply a larger array of goods at improved terms of trade.

• "Globalization and Emerging Markets: With or without Crash?"  2006, with Hélène Rey. A data appendix is here. American Economic Review, December, vol 96, n5, 1631-51. Abstract: We analyze the effects of financial and trade globalization on the likelihood of financial crashes in emerging markets. While trade globalization always makes crashes less likely, financial globalization may make them more likely, especially when trade costs are high. Pessimistic expectations can be self-fulfilling and lead to a collapse in demand for goods and assets. Such a crash comes with a current account reversal and drops in income and investment. Lower-income countries are more prone to such demand-based financial crises. A quantitative evaluation shows our model is consistent with the main stylized facts of financial crashes in emerging markets.

• "Subsidies to Poor Regions and Inequalities: Some Unpleasant Arithmetic", with Vincent Dupont, 2006, Journal of Economic Geography, April 2006; 6: 223 - 240

• "The Geography of inequalities in Europe",  2005, Swedish Economic Policy Review. Volume 12.

• " Financial Super-Markets: Size Matters for Asset Trade", 2004, with Hélène Rey. Journal of International Economics, 64, 335– 361.

• "Terrorism and the Resilience of Cities", with James Harrigan, novembre 2002, Economic Policy Review, Federal Reserve Bank of New York. Volume 8 number 2.

• "Coordination, Cooperation, Contagion and Currency Crises", 2001, with Olivier Loisel, Journal of International Economics 53 , 399-419

• "Global Economic Divergence, Trade and Industrialisation: The Geography of Growth Takeoffs", with Richard Baldwin and Gianmarco Ottaviano,  2001, Journal of Economic Growth, 6: March, 5-37.

• "Growth and Agglomeration", 2001, with Gianmarco Ottaviano, International Economic Review, November, 42: 947-968

• "Financial Integration and Asset Returns", with Hélène Rey, 2000, European Economic Review, June, vol 44/7, p. 1327-1350.

• "Optimal Stabilization Policy in the Presence of Learning by Doing", with Carol Rogers, 2000, Journal of Public Economic Theory, 2 (2), 213-240.

• "Short Term Economic Instability and Long Term Growth", with Carol Rogers, 2000, European Economic Review (44) 2, pp. 359-381.

• "Public Policies, Regional Inequalities and Growth", Journal of Public Economics, (73)1 (1999) pp. 85-105; (reedited in book Kluwer)

• "Growing Locations: Industry Location in a Model of Endogenous Growth", 1999, with Gianmarco Ottaviano, European Economic Review (43) 2, pp. 281-302

• "Can Regional Policies Affect Growth and Geography in Europe?", 1998, World Economy vol. 21, no. 6, 757-774. (PDF)

• "Coopération Internationale et Crises de Change Spéculatives", 1999, with Olivier Loisel, Revue Economique

• "The Exchange Rate Policy of the Euro: A Matter of Size?", 1998, Journal of the Japanese and International Economies, 12, 455-482. Also in French in Revue d’Economie Politique, 1998, 108 (2), 195-225.

• "Stabilization Policy, Growth and Learning by Doing", with Carol Rogers, 1997, Oxford Economic Papers, 2, volume 49, 152-166.

• "Are Capital Flows Consistent with the Neoclassical Growth Model? Evidence from a Cross-section of Developing Countries", 1996, (with Stefano Manzocchi), CEPR Discussion Paper N° 1400. Published (in French) in Economie Internationale, n° 72, 1997, p. 7-24.

• "L'Importance des Exclus de l'Intégration Monétaire en Europe", 1996, Revue Economique, volume 47, n° 3, 807-817.

• "The Geography of Multi-Speed Europe", with Gianmarco Ottaviano, CEPR Discussion paper 1292, in French in Economie Internationale, N°67, 1996, 45-65 .

• "A Sequential Approach to Regional Integration: the European Union and Eastern Europe",1996, European Journal of Political Economy. Volume 12, 581-598.

• "Industrial Location and Public Infrastructure", with Carol Rogers, 1995, Journal of International Economics, volume 39, p 335-351.

• "Free-Riding, Convergence and Two-Speed Monetary Unification in Europe", August 1995, European Economic Review, volume 39, No. 7, 1345-1364.

• "Monetary Policy and Country Size", October 1994, Journal of International Money and Finance, Volume 13, No 5, p. 573-86.

Books

• The economics of Clusters: Lessons fron the French Experience" with Gilles Duranton, Thierry Mayer and Florian Mayneris, 2010, Oxford University Press, 192 pages. This book looks at the mechanisms at work behind cluster dynamics, the gains that can be expected from increased clustering, and the determinants of cluster policies. Focusing on France, it provides a theoretical and empirical study of clusters, their success and failures, and the policy lessons that can be applied to the wider international community. This book shows that, while gains from clusters do exist, some firms tend to cluster too much and that spatial agglomeration is only successful to a point, after which congestion effects can offset these gains.

• "Les pôles de compétitivité: que peut-on en attendre?" 2008, with Gilles Duranton, Thierry Mayer and Florian Mayneris, CEPREMAP/ENS. (couverture de presse: Le Monde, L'Express)

• La mondialisation est-elle un facteur de paix? 2006 avec Thierry Mayer et Matthias Thoenig. Edition de la rue d'Ulm (ENS)/CEPREMAP

• Economic Geography and Public Policy  PRINCETON UNIVERSITY PRESS. New in paperback 2005 with Richard Baldwin, Rikard Forslid, Gianmarco Ottaviano and Frédéric Robert-Nicoud. Outline of the book and some draft (uncorrected) chapters; chapter 2 (Core-Periphery Model); chapter 3 (The Footloose Capital model); chapter 12 (Unilateral Trade Policy); chapter 14 (Preferential Trade agreements)

Chapters in books, policy papers

• Financial crises and African Trade, 2011, chapter in "Trade Finance During the Great Trade Collapse; Mariem Malouche & Jean-Pierre Chauffour ; editors, World Bank.

• Regional and Glogal Financial Integration: an Analytical Framework, in Devereux, M., P. Lane, C.Y. Park, and S.J. Wei. (Eds.). The Dynamics of Asian Financial Integration, Routledge Studies in the Modern World Economy (2011)

• Seize nouvelles questions d'économie contemporaine, 2010, chapitre (co-écrit avec Thierry Mayer) sur "L'effondrement du commerce dans la crise mondiale de 2008-2009: a qui la faute?", Albin Michel, editeurs, Philippe Askenazy et Daniel Cohen.

• Comment on International Reserves and Underdeveloped Capital Markets: Kathryn M. E. Dominguez, in NBER international Seminar in Macroeconomics 2009.

• International Trade in Financial Assets, 2009, in The euro at ten: the next global currency? edited by Jean Pisani-Ferry and Adam Posen

• "Coordination of Industrial Policy in the European Union" with Richard Baldwin. In EIB Papers, Vol. 11/ No.1 2006. European Investment Bank.

• Comment on "Improving fiscal policy in the EU: the case for independent forecasts" by Lars Jonung1 and Martin Larch, in Economic Policy,  Issue 47, July 2006

• Comment  on "The impact of rules of origin on trade flows" by Patricia Augie1, Michael Gasiorek and Charles Lai Tong  in Economic Policy, Volume 20 Page 567 - July 2005

• Comment  on "Financial market integration and economic growth in the EU" by  Luigi Guiso, Tullio Jappelli, Mario Padula, Marco Pagano, in Economic Policy, Issue 40, October 2004

• "Agglomeration and Regional Growth" with Richard Baldwin, 2003, CEPR discussion paper 3960, chapter for the North Holland Handbook of Regional and Urban Economics: Cities and Geography edited by Vernon Henderson and Jacques-François Thisse

• "The Core Periphery Model : Key Features and Effects" with Richard Baldwin, Rikard Forslid, Gianmarco Ottaviano and Frédéric Robert-Nicoud, 2004, in Heijdra and Brakman (eds), The Monopolistic Competition Revolution in Retrospect, Cambridge University Press.

• "Public Policies and Economic Geography", in Funk and Pizzati (eds), European Integration, Regional Policy and Growth, World Bank 2003.

• "Review of Kevin H. O’Rourke and Jeffrey G. Williamson, MIT Press, Cambridge, 1999. Globalization and History: The Evolution of a Nineteenth-Century Atlantic Economy", Journal of Economic Geography, July 2002, 369-372

• "La Globalisation Financière", text of the conference for l'Université de Tous Les Savoirs (UTLS) of 29 April 2000. (PDF) (in French) Odile Jacob editor, Paris.

• " Two Waves of Globalisation: Superficial Similarities, Fundamental Differences ", with Richard Baldwin, NBER working paper 6904. Published in Globalization and Labor, edited by H. Siebert, 1999. p 3-58. working paper version (PDF)    Italian translation reprinted in Crescita regionale ed urbana nel mercato globale: Modelli, politiche, processi di valutazione, edited by Fabio Mazzola and Mario Maggioni, FrancoAngeli, Milan, 2001.

• "The Role of Public Policy in the Process of Regional Convergence", 2000, EIB Papers

• " Are European Regional Policies Delivering?" EIB Papers, Volume 4 No 2, 1999; working paper version (PDF)

• "Quel cadre conceptuel pour les politiques régionales en Europe?", actes de colloque, treizième congrès des économistes belges de langue française, p. 79-97.

• Comment on Fatas paper ("Does EMU need a fiscal federation?"), Economic Policy, April 1998, p. 195-197. Parts of the discussion are interesting in view of current debates on the euro crisis.

• "Choosing Central Bankers in Europe", 1995, in G. Schneider, P. A. Weitsman and T. Bernauer (eds.) Towards a New Europe: Stops and Starts in Regional Integration, Greenwood, Westport, p 153-172.

• "Trade Effects of Regional Aid", with Carol Rogers, 1995 in R. Baldwin, P. Haaparanta and J. Kiander (eds.) Expanding Membership of the European Union, CEPR/ Cambridge University Press, p 166-88. 

Recent Policy Papers

•  A la recherche des parts de marché perdues, Note du CAE, Mai 2015, avec Maria Bas, Lionel Fontagné et Thierry Mayer

• Promouvoir l’égalité des chances à travers le territoire, Note du CAE, Février 2015 avec Philippe Askenazy

• L'euro dans la "guerre des monnaies", Note du CAE, janvier 2014, avec Agnès Bénassy-Quéré, Pierre-Olivier Gourinchas  et Guillaume Plantin. English version on VOX.EU

• Les exportateurs francais face aux variations de l'euro, avec Jérôme Héricourt et Gianluca Orefice, La lettre du Cepii.

• Énergie et compétitivité, Note du CAE, mai 2013 , avec Dominique Bureau et Lionel Fontagné. English version "Energy and competitiveness"