Philippe Aghion
Personal Information
Description
French economist who shared the 2025 Nobel Prize in Economics with two others.
Books
Financial development and the instability of open economies
"This paper introduces a framework for analyzing the role of financial factors as a source of instability in small open economies. Our basic model is a dynamic open economy model with a tradeable good produced with capital and a country-specific factor. We also assume that firms face credit constraints, with the constraint being tighter at a lower level of financial development. A basic implication of this model is that economies at an intermediate level of financial development are more unstable than either very developed or very underdeveloped economies. This is true both in the sense that temporary shocks have large and persistent effects and also in the sense that these economies can exhibit cycles. Thus, countries that are going through a phase of financial development may become more unstable in the short run. Similarly, full capital account liberalization may destabilize the economy in economies at an intermediate level of financial development: phases of growth with capital inflows are followed by collapse with capital outflows. On the other hand, foreign direct investment does not destabilize"--National Bureau of Economic Research web site.
The effect of financial development on convergence
"We introduce imperfect creditor protection in a multi-country version of Schumpeterian growth theory with technology transfer. The theory predicts that the growth rate of any country with more than some critical level of financial development will converge to the growth rate of the world technology frontier, and that all other countries will have a strictly lower long-run growth rate. The theory also predicts that in a country that converges to the frontier growth rate, financial development has a positive but eventually vanishing effect on steady-state per-capita GDP relative to the frontier. We present cross-country evidence supporting these two implications. In particular, we find a significant and sizeable effect of an interaction term between initial per-capita GDP (relative to the United States) and a financial intermediation measure in an otherwise standard growth regression, implying that the likelihood of converging to the U.S. growth rate increases with financial development. We also find that, as predicted by the theory, the direct effect of financial intermediation in this regression is not significantly different from zero. These findings are robust to alternative conditioning sets, estimation procedures and measures of financial development"--National Bureau of Economic Research web site.
Negotiating free trade
"We develop a dynamic bargaining model in which a leading country endogenously decides whether to sequentially negotiate free trade agreements with subsets of countries or engage in simultaneous multilateral bargaining with all countries at once. We show how the structure of coalition externalities shapes the choice between sequential and multilateral bargaining, and we identify circumstances in which the grand coalition is the equilibrium outcome, leading to worldwide free trade. A model of international trade is then used to illustrate equilibrium outcomes and how they depend on the structure of trade and protection. Global free trade is not achieved when the political-economy motive for protection is sufficiently large. Furthermore, the model generates both building bloc' and stumbling bloc' effects of preferential trade agreements. In particular, we describe an equilibrium in which global free trade is attained only when preferential trade agreements are permitted to form (a building bloc effect), and an equilibrium in which global free trade is attained only when preferential trade agreements are forbidden (a stumbling bloc effect). The analysis identifies conditions under which each of these outcomes emerges"--National Bureau of Economic Research web site.
The economics of growth
"This comprehensive introduction to economic growth presents the main facts and puzzles about growth, proposes simple methods and models needed to explain these facts, acquaints the reader with the most recent theoretical and empirical developments, and provides tools with which to analyze policy design. The treatment of growth theory is fully accessible to students with a background no more advanced than elementary calculus and probability theory; the reader need not master all the subtleties of dynamic programming and stochastic processes to learn what is essential about such issues as cross-country convergence, the effects of financial development on growth, and the consequences of globalization. The book, which grew out of courses taught by the authors at Harvard and Brown universities, can be used both by advanced undergraduate and graduate students, and as a reference for professional economists in government or international financial organizations. The Economics of Growth first presents the main growth paradigms: the neoclassical model, the AK model, Romer's product variety model, and the Schumpeterian model. The text then builds on the main paradigms to shed light on the dynamic process of growth and development, discussing such topics as club convergence, directed technical change, the transition from Malthusian stagnation to sustained growth, general purpose technologies, and the recent debate over institutions versus human capital as the primary factor in cross-country income differences. Finally, the book focuses on growth policies—analyzing the effects of liberalizing market competition and entry, education policy, trade liberalization, environmental and resource constraints, and stabilization policy—and the methodology of growth policy design."--PUBLISHER'S DESCRIPTION.
Endogenous Growth Theory
Whereas other books on endogenous growth stress a particular aspect, such as trade or convergence, this book provides a comprehensive survey of the theoretical and empirical debates raised by modern growth theory. Advanced economies have experienced a tremendous increase in material well- being since the industrial revolution. Modern innovations such as personal computers, laser surgery, jet airplanes, and satellite communication have made us rich and transformed the way we live and work. But technological change has also brought with it a variety of social problems. It has been blamed at various times for increasing wage and income inequality, unemployment, obsolescence of physical and human capital, environmental deterioration, and prolonged recessions. To understand the contradictory effects of technological change on the economy, one must delve into structural details of the innovation process to analyze how laws, institutions, customs, and regulations affect peoples' incentive and ability to create new knowledge and profit from it. To show how this can be done, Philippe Aghion and Peter Howitt make use of Schumpeter's concept of creative destruction, the competitive process whereby entrepreneurs constantly seek new ideas that will render their rivals' ideas obsolete. Whereas other books on endogenous growth stress a particular aspect, such as trade or convergence, this book provides a comprehensive survey of the theoretical and empirical debates raised by modern growth theory. It develops a powerful engine of analysis that sheds light not only on economic growth per se, but on the many other phenomena that interact with growth, such as inequality, unemployment, capital accumulation, education, competition, natural resources, international trade, economic cycles, and public policy. source
Choosing electoral rules
"This paper studies the choice of electoral rules, in particular, the question of minority representation. Majorities tend to disenfranchise minorities through strategic manipulation of electoral rules. With the aim of explaining changes in electoral rules adopted by US cities (particularly in the South), we show why majorities tend to adopt "winner-take-all" city-wide rules (at-large elections) in response to an increase in the size of the minority when the minority they are facing is relatively small. In this case, for the majority it is more effective to leverage on its sheer size instead of risking to concede representation to voters from minority-elected districts. However, as the minority becomes larger (closer to a fifty-fifty split), the possibility of losing the whole city induces the majority to prefer minority votes to be confined in minority-packed districts. Single-member district rules serve this purpose. We show empirical results consistent with these implications of the model"--National Bureau of Economic Research web site.
Handbook of economic growth
"The Handbook of Economic Growth provides a broad review of the research topics, empirical findings, and methods that comprise modern growth economics. The chapters, written by research leaders, summarize and evaluate recent advances while explaining where further research might be profitable. With analyses that are provocative and controversial because they are so directly relevant to public policy and private decision-making, volume 2A and 2B upholds the standard for excellence in applied economics set by Volumes 1A and 1B (2005). It offers definitive theoretical and empirical scholarship about growth economics. It presents as a guiding principle the search for a theoretical framework consistent with the theories and data that describe growth economics. It familiarizes readers with common empirical methods and empirical results"--provided by publisher.
Academic freedom, private-sector focus, and the process of innovation
"We develop a model that clarifies the respective advantages and disadvantages of academic and private-sector research. Our model assumes full protection of intellectual property rights at all stages of the development process, and hence does not rely on lack of appropriability or spillovers to generate a rationale for academic research. Instead, we focus on control-rights considerations, and argue that the fundamental tradeoff between academia and the private sector is one of creative control versus focus. By serving as a precommitment mechanism that allows scientists to freely pursue their own interests, academia can be indispensable for early-stage research. At the same time, the private sector's ability to direct scientists towards higher-payoff activities makes it more attractive for later-stage research"--National Bureau of Economic Research web site.