Most Popular Books by Daron Acemoglu

Health expenditures as a share of GDP have more than tripled over the last half century. A common conjecture is that this is primarily a consequence of rising real per capita income, which more than doubled over the same period. We investigate this hypothesis empirically by instrumenting for local area income with time-series variation in global oil prices between 1970 and 1990 interacted with cross-sectional variation in the oil reserves across different areas of the Southern United States. This strategy enables us to capture both the partial equilibrium and the local general equilibrium effects of an increase in income on health expenditures. Our central estimate is an income elasticity of 0.7, with an elasticity of 1.1 as the upper end of the 95 percent confidence interval. Point estimates from alternative specifications fall on both sides of our central estimate, but are almost always less than 1. We also present evidence suggesting that there are unlikely to be substantial national or global general equilibrium effects of rising income on health spending, for example through induced innovation. Our overall reading of the evidence is that rising income is unlikely to be a major driver of the rising health share of GDP.

Almost all democratic societies evolved socially and politically out of authoritarian and nondemocratic regimes. These changes not only altered the allocation of economic resources in society but also the structure of political power. In this paper, we develop a framework for studying the dynamics of political and social change. The society consists of agents that care about current and future social arrangements and economic allocations; allocation of political power determines who has the capacity to implement changes in economic allocations and future allocations of power. The set of available social rules and allocations at any point in time is stochastic. We show that political and social change may happen without any stochastic shocks or as a result of a shock destabilizing an otherwise stable social arrangement. Crucially, the process of social change is contingent (and history-dependent): the timing and sequence of stochastic events determine the long-run equilibrium social arrangements. For example, the extent of democratization may depend on how early uncertainty about the set of feasible reforms in the future is resolved.

(Cont.) Under some additional assumptions on preferences, these results generalize to the case when the government is benevolent but unable to commit to future tax policies. We conclude by providing a brief comparison of centralized mechanisms operated by self-interested rulers to anonymous markets. Keywords: dynamic incentive problems, mechanism design, optimal taxation, political economy, revelation principle. JEL Classifications: H11, H21, E61, P16.

This paper proposes a new framework for studying the interplay between culture and institutions. We follow the recent sociology literature and interpret culture as a "repertoire", which allows rich cultural responses to changes in the environment and shifts in political power. Specifically, we start with a culture set, which consists of attributes and the feasible connections between them. Combinations of attributes produce cultural configurations, which provide meaning, interpretation and justification for individual and group actions. Cultural figurations also legitimize and support different institutional arrangements. Culture matters as it shapes the set of feasible cultural figurations and via this channel institutions. Yet, changes in politics and institutions can cause a rewiring of existing attributes, generating very different cultural configurations. Cultural persistence may result from the dynamics of political and economic factors -- rather than being a consequence of an unchanging culture. We distinguish cultures by how fluid they are -- whereby more fluid cultures allow a richer set of cultural configurations. Fluidity in turn depends on how specific (vs. abstract) and entangled (vs. free-standing) attributes in a culture set are. We illustrate these ideas using examples from African, England, China, the Islamic world, the Indian caste system and the Crow. In all cases, our interpretation highlights that culture becomes more of a constraint when it is less fluid (more hardwired), for example because its attributes are more specific or entangled. We also emphasize that less fluid cultures are not necessarily "bad cultures", and may create a range of benefits, though they may reduce the responsiveness of culture to changing circumstances. In many instances, including in the African, Chinese and English cases, we show that there is a lot of fluidity and very different, almost diametrically-opposed, cultural configurations are feasible, often compete with each other for acceptance and can gain the upper hand depending on political factors.

In this essay, we provide a simple conceptual framework to elucidate the forces that lead to institutional persistence and change. Our framework is based on a dynamic game between different groups, who care both about current policies and institutions and future policies, which are themselves determined by current institutional choices, and clarifies the forces that lead to the most extreme form of institutional persistence ("institutional stasis") and the potential drivers of institutional change. We further study the strategic stability of institutions, which arises when institutions persist because of fear of subsequent, less beneficial changes that would follow initial reforms. More importantly, we emphasize that, despite the popularity of ideas based on institutional stasis in the economics and political science literatures, most institutions are in a constant state of flux, but their trajectory may still be shaped by past institutional choices, thus exhibiting "path-dependent change", so that initial conditions determine both the subsequent trajectories of institutions and how they respond to shocks. We conclude the essay by discussing how institutions can be designed to bolster stability, the relationship between social mobility and institutions, and the interplay between culture and institutions.

This paper presents an analysis of what types of values, especially in regards to obedience vs. independence, families impart to their children and how these values interact with social mobility. In the model, obedience is a useful characteristic for employers, especially when wages are low, because independent workers require more incentives (when wages are high, these incentives are automatic). Hence, in low-wage environments, low-income families will impart values of obedience to their children to prevent disadvantaging them in the labor market. To the extent that independence is useful for entrepreneurial activities, this then depresses their social mobility. High-income and privileged parents, on the other hand, always impart values of independence, since they expect that their children can enter into higher-income entrepreneurial (or managerial) activities thanks to their family resources and privileges. I also discuss how political activity can be hampered when labor market incentives encourage greater obedience and how this can generate multiple steady states with different patterns of social hierarchy and mobility.

Transformative technologies like generative artificial intelligence promise to accelerate productivity growth across many sectors, but they also present new risks from potential misuse. We develop a multi-sector technology adoption model to study the optimal regulation of transformative technologies when society can learn about these risks over time. Socially optimal adoption is gradual and convex. If social damages are proportional to the productivity gains from the new technology, a higher growth rate leads to slower optimal adoption. Equilibrium adoption is inefficient when firms do not internalize all social damages, and sector-independent regulation is helpful but generally not sufficient to restore optimality.

Artificial Intelligence is set to influence every aspect of our lives, not least the way production is organized. AI, as a technology platform, can automate tasks previously performed by labor or create new tasks and activities in which humans can be productively employed. Recent technological change has been biased towards automation, with insufficient focus on creating new tasks where labor can be productively employed. The consequences of this choice have been stagnating labor demand, declining labor share in national income, rising inequality and lower productivity growth. The current tendency is to develop AI in the direction of further automation, but this might mean missing out on the promise of the "right" kind of AI with better economic and social outcomes.

will be the ruling coalition and conditions under which the most powerful individuals will not be included in the ruling coalition. We also use this framework to discuss endogenous party formation.

The standard approach to policy-making and advice in economics implicitly or explicitly ignores politics and political economy, and maintains that if possible, any market failure should be rapidly removed. This essay explains why this conclusion may be incorrect; because it ignores politics, this approach is oblivious to the impact of the removal of market failures on future political equilibria and economic efficiency, which can be deleterious. We first outline a simple framework for the study of the impact of current economic policies on future political equilibria and indirectly on future economic outcomes. We then illustrate the mechanisms through which such impacts might operate using a series of examples. The main message is that sound economic policy should be based on a careful analysis of political economy and should factor in its influence on future political equilibria. Keywords: economic policy, market failures, policy advice, political economy, politics. JEL Classification: P16, P48, O20.

The paper provides a political economy theory of the Kuznets curve. When development leads to increasing inequality, this can induce political instability and force democratization on political elites. Democratization leads to institutional changes which encourage redistribution and reduce inequality. Nevertheless, development does not necessarily induce a Kuznets curve, and it is shown that development may be associated with two types of nondemocratic paths: An "autocratic disaster," with high inequality and low output, and an "East Asian Miracle," with low inequality and high output. These arise either because inequality does not increase with development, or because the degree of political mobilization is low.

This paper provides evidence from the US and Denmark that managers with a business degree ("business managers") reduce their employees' wages. Within five years of the appointment of a business manager, wages decline by 6% and the labor share by 5 percentage points in the US, and by 3% and 3 percentage points in Denmark. Firms appointing business managers are not on differential trends and do not enjoy higher output, investment, or employment growth thereafter. Using manager retirements and deaths and an IV strategy based on the diffusion of the practice of appointing business managers within industry, region and size quartile cells, we provide additional evidence that these are causal effects. We establish that the proximate cause of these (relative) wage effects are changes in rent-sharing practices following the appointment of business managers. Exploiting exogenous export demand shocks, we show that non-business managers share profits with their workers, whereas business managers do not. But consistent with our first set of results, these business managers show no greater ability to increase sales or profits in response to exporting opportunities. Finally, we use the influence of role models on college major choice to instrument for the decision to enroll in a business degree in Denmark and show that our estimates correspond to causal effects of practices and values acquired in business education - rather than the differential selection into business education of individuals unlikely to share rents with workers.

Bloom, Canning, and Fink (2014) argue that the results in Acemoglu and Johnson (2006, 2007) are not robust because initial level of life expectancy (in 1940) should be included in our regressions of changes in GDP per capita on changes in life expectancy. We assess their claims controlling for potential lagged effects of initial life expectancy using data from 1900, employing a nonlinear estimator suggested by their framework, and using information from microeconomic estimates on the effects of improving health. There is no evidence for a positive effect of life expectancy on GDP per capita in this important historical episode.

We summarize a framework for the study of the implications of automation and AI on the demand for labor, wages, and employment. Our task-based framework emphasizes the displacement effect that automation creates as machines and AI replace labor in tasks that it used to perform. This displacement effect tends to reduce the demand for labor and wages. But it is counteracted by a productivity effect, resulting from the cost savings generated by automation, which increase the demand for labor in non-automated tasks. The productivity effect is complemented by additional capital accumulation and the deepening of automation (improvements of existing machinery), both of which further increase the demand for labor. These countervailing effects are incomplete. Even when they are strong, automation in-creases output per worker more than wages and reduce the share of labor in national income. The more powerful countervailing force against automation is the creation of new labor-intensive tasks, which reinstates labor in new activities and tends to in-crease the labor share to counterbalance the impact of automation. Our framework also highlights the constraints and imperfections that slow down the adjustment of the economy and the labor market to automation and weaken the resulting productivity gains from this transformation: a mismatch between the skill requirements of new technologies, and the possibility that automation is being introduced at an excessive rate, possibly at the expense of other productivity-enhancing technologies. Keywords: AI, automation, displacement effect, labor demand, inequality, productivity, tasks, technology, wages.

This paper argues that openness to new, unconventional and disruptive ideas has a first-order impact on creative innovations; innovations that break new ground in terms of knowledge creation. After presenting a motivating model focusing on the choice between incremental and radical innovation, and on how managers of different ages and human capital are sorted across different types of firms, we provide cross-country, firm-level and patent-level evidence consistent with this pattern. Our measures of creative innovations proxy for innovation quality (average number of citations per patent) and creativity (fraction of superstar innovators, the likelihood of a very high number of citations, and generality of patents). Our main proxy for openness to disruption is manager age. This variable is based on the idea that only companies or societies open to such disruption will allow the young to rise up within the hierarchy. Using this proxy at the country, firm or patent level, we present robust evidence that openness to disruption is associated with more creative innovations. Keywords: corporate culture, creative destruction, creativity, economic growth, entrepreneurship, individualism, innovation, openness to disruption. openness to disruption openness to disruption. JEL Classification: O40, O43, O33, P10, P16, Z1

This paper develops the thesis that credit market frictions may be an important contributor to high unemployment in Europe. When a change in the technological regime necessitates the creation of new firms, this can happen relatively rapidly in the U.S. where credit markets function efficiently. In contrast, in Europe, job creation is constrained by credit market imperfections, so unemployment rises and remains high for an extended period. The data show that there has not been slower growth in the most credit dependent industries in Europe relative to the U.S., but the share of employment in these industries is lower than in the U.S.. This suggests that although credit market imperfections are unlikely to have been the major cause of the increase in European unemployment, they may have played some role in limiting European employment growth.

We document a statistical association between the severity of the persecution and mass murder of Jews (the Holocaust) by the Nazis during World War II and long-run economic and political outcomes within Russia. Cities that experienced the Holocaust most intensely have grown less, and both cities and administrative districts (oblasts) where the Holocaust had the largest impact have worse economic and political outcomes since the collapse of the Soviet Union. Although we cannot rule out the possibility that these statistical relationships are caused by other factors, the overall patterns appear generally robust. We provide evidence on one possible mechanism that we hypothesize may link the Holocaust to the present - the change it induced in the social structure, in particular the size of the middle class, across different regions of Russia. Before World War II, Russian Jews were predominantly in white collar (middle class) occupations and the Holocaust appears to have had a large negative effect on the size of the middle class after the war.

We propose a model of the emergence of equality before the law. A society can support “effort” (“cooperation”, “pro-social behavior”) using the “carrot” of future cooperation or the “stick” of coercive punishment. Community enforcement relies only on the carrot and involves low coercion, low inequality, and low effort. A society in which the elite control the means of violence supplements the carrot with the stick, and involves high coercion, high inequality, and high effort. In this regime, elites are privileged: they are not subject to the same coercive punishments as non-elites. We show that it may be optimal -- even from the viewpoint of the elite -- to establish equality before the law, where all agents are subject to the same coercive punishments. The central mechanism is that equality before the law increases elites’ effort, which in turn encourages even higher effort from non-elites. Equality before the law combines high coercion and low inequality -- in our baseline model, elites exert the same level of effort as non-elites. Factors that make the emergence of equality before the law more likely include limits on the extent of coercion, greater marginal returns to effort, increases in the size of the elite group, greater political power for non-elites, and under some additional conditions, lower economic inequality.

External certification of workplace skills obtained through on-the-job training is widespread in many countries. This may indicate that training is financed by workers, and certification serves to assure the quality of the training offered by the firm. However, other evidence shows that general training is financed by firms, especially in Germany. We show in this paper that external certification of training may also be necessary for an equilibrium with firm-sponsored training. Firm financing of training is only possible if firms have monopsony power over the workers after training. If the training firm can extract too much of the employment rents, however, workers may not have sufficient incentives to put forth effort during training. Certification increases the values of training to the outside market, and hence to workers, making firm-sponsored training possible.

This paper constructs a model of non-balanced economic growth. The main economic force is the combination of differences in factor proportions and capital deepening. Capital deepening tends to increase the relative output of the sector with a greater capital share, but simultaneously induces a reallocation of capital and labor away from that sector. We first illustrate this force using a general two-sector model. We then investigate it further using a class of models with constant elasticity of substitution between two sectors and Cobb-Douglas production functions in each sector. In this class of models, non-balanced growth is shown to be consistent with an asymptotic equilibrium with constant interest rate and capital share in national income. We also show that for realistic parameter values, the model generates dynamics that are broadly consistent with US data. In particular, the model generates more rapid growth of employment in less capital-intensive sectors, more rapid growth of real output in more capital-intensive sectors and aggregate behavior in line with the Kaldor facts. Finally, we construct and analyze a model of quot;non-balanced endogenous growth,quot; which extends the main results of the paper to an economy with endogenous anddirected technical change. This model shows that equilibrium will typically involve endogenous non-balanced technological progress.

This paper proposes a new framework for studying the interplay between culture and institutions. We follow the recent sociology literature and interpret culture as a "repertoire", which allows rich cultural responses to changes in the environment and shifts in political power. Specifically, we start with a culture set, which consists of attributes and the feasible connections between them. Combinations of attributes produce cultural configurations, which provide meaning, interpretation and justification for individual and group actions. Cultural figurations also legitimize and support different institutional arrangements. Culture matters as it shapes the set of feasible cultural figurations and via this channel institutions. Yet, changes in politics and institutions can cause a rewiring of existing attributes, generating very different cultural configurations. Cultural persistence may result from the dynamics of political and economic factors -- rather than being a consequence of an unchanging culture. We distinguish cultures by how fluid they are -- whereby more fluid cultures allow a richer set of cultural configurations. Fluidity in turn depends on how specific (vs. abstract) and entangled (vs. free-standing) attributes in a culture set are. We illustrate these ideas using examples from African, England, China, the Islamic world, the Indian caste system and the Crow. In all cases, our interpretation highlights that culture becomes more of a constraint when it is less fluid (more hardwired), for example because its attributes are more specific or entangled. We also emphasize that less fluid cultures are not necessarily "bad cultures", and may create a range of benefits, though they may reduce the responsiveness of culture to changing circumstances. In many instances, including in the African, Chinese and English cases, we show that there is a lot of fluidity and very different, almost diametrically-opposed, cultural configurations are feasible, often compete with each other for acceptance and can gain the upper hand depending on political factors.

We develop a microeconomic model of endogenous growth where clean and dirty technologies compete in production and innovation. in the sense that research can be directed to either clean or dirty technologies. If dirty technologies are more advanced to start with, the potential transition to clean technology can be difficult both because clean research must climb several rungs to catch up with dirty technology and because this gap discourages research effort directed towards clean technologies. Carbon taxes and research subsidies may nonetheless encourage production and innovation in clean technologies, though the transition will typically be slow. We characterize certain general properties of the transition path from dirty to clean technology. We then estimate the model using a combination of regression analysis on the relationship between R&D and patents, and simulated method of moments using microdata on employment, production, R&D, firm growth, entry and exit from the US energy sector. The model's quantitative implications match a range of moments not targeted in the estimation quite well. We then characterize the optimal policy path implied by the model and our estimates. Optimal policy makes heavy use of research subsidies as well as carbon taxes. We use the model to evaluate the welfare consequences of a range of alternative policies.

We develop a multi-risk SIR model (MR-SIR) where infection, hospitalization and fatality rates vary between groups--in particular between the "young”, "the middle-aged” and the "old”. Our MR-SIR model enables a tractable quantitative analysis of optimal policy similar to those already developed in the context of the homogeneous-agent SIR models. For baseline parameter values for the COVID-19 pandemic applied to the US, we find that optimal policies differentially targeting risk/age groups significantly outperform optimal uniform policies and most of the gains can be realized by having stricter lockdown policies on the oldest group. For example, for the same economic cost (24.3% decline in GDP), optimal semi-targeted or fully-targeted policies reduce mortality from 1.83% to 0.71% (thus, saving 2.7 million lives) relative to optimal uniform policies. Intuitively, a strict and long lockdown for the most vulnerable group both reduces infections and enables less strict lockdowns for the lower-risk groups. We also study the impacts of social distancing, the matching technology, the expected arrival time of a vaccine, and testing with or without tracing on optimal policies. Overall, targeted policies that are combined with measures that reduce interactions between groups and increase testing and isolation of the infected can minimize both economic losses and deaths in our model.

The introduction of Medicare in 1965 was the single largest change in health insurance coverage in U.S. history. Many economists and commentators have conjectured that the introduction of Medicare may have also been an important impetus for the development of new drugs that are now commonly used by the elderly and have substantially extended their life expectancy. In this paper, we investigate whether Medicare induced pharmaceutical innovations directed towards the elderly. Medicare could have played such a role only if two conditions were met. First, Medicare would have to increase drug spending by the elderly. Second, the pharmaceutical companies would have to respond to the change in market size for drugs caused by Medicare by changing the direction of their research. Our empirical work finds no evidence of a "first-stage" effect of Medicare on prescription drug expenditure by the elderly. Correspondingly, we also find no evidence of a shift in pharmaceutical innovation towards therapeutic categories most used by the elderly. On the whole, therefore, our evidence does not provide support for the hypothesis that Medicare had a major effect on the direction of pharmaceutical innovation.

We document that between 50% and 70% of changes in the US wage structure over the last four decades are accounted for by the relative wage declines of worker groups specialized in routine tasks in industries experiencing rapid automation. We develop a conceptual framework where tasks across a number of industries are allocated to different types of labor and capital. Automation technologies expand the set of tasks performed by capital, displacing certain worker groups from employment opportunities for which they have comparative advantage. This framework yields a simple equation linking wage changes of a demographic group to the task displacement it experiences. We report robust evidence in favor of this relationship and show that regression models incorporating task displacement explain much of the changes in education differentials between 1980 and 2016. Our task displacement variable captures the effects of automation technologies (and to a lesser degree offshoring) rather than those of rising market power, markups or deunionization, which themselves do not appear to play a major role in US wage inequality. We also propose a methodology for evaluating the full general equilibrium effects of task displacement (which include induced changes in industry composition and ripple effects as tasks are reallocated across different groups). Our quantitative evaluation based on this methodology explains how major changes in wage inequality can go hand-in-hand with modest productivity gains.

Many states in Latin America, Africa and Asia lack the monopoly of violence, identified by Max Weber as the foundation of the state, and thus the capacity to govern effectively. In this paper we develop a new perspective on the establishment of the monopoly of violence and the formation of the state. We build a model to explain the incentive of central states to eliminate non-state armed actors (paramilitaries) in a democracy. The model is premised on the idea that paramilitaries may choose to and can influence elections. Since paramilitaries have preferences over policies, this reduces the incentives of the politicians they favor to eliminate them. The model also shows that while in non-paramilitary areas policies are targeted at citizens, in paramilitary controlled areas they are targeted at paramilitaries. We then investigate the predictions of our model using data from Colombia between 1991 and 2006. We first present regression and case study evidence supporting our postulate that paramilitary groups can have significant effects on elections for the legislature and the executive. Next, we show that the evidence is also broadly consistent with the implication of the model that paramilitaries tend to persist to the extent that they deliver votes to candidates for the executive whose preferences are close to theirs and that this effect is larger in areas where the Presidential candidate would have otherwise not done as well. These results illustrate that, consistent with our model, there appears to be a symbiotic relationship between some executives and paramilitaries. Finally, we use roll-call votes to illustrate a possible 'quid pro quo' between the executive and paramilitaries in Colombia. Keywords: State Capacity, Violence, Elections. JEL Classifications: D7, H11.

A notable feature of post-World War II civil wars is their very long average duration. We provide a theory of the persistence of civil wars. The civilian government can successfully defeat rebellious factions only by creating a relatively strong army. In weakly-institutionalized polities this opens the way for excessive influence or coups by the military. Civilian governments whose rents are largely unaffected by civil wars then choose small and weak armies that are incapable of ending insurrections. Our framework also shows that when civilian governments need to take more decisive action against rebels, they may be forced to build over-sized armies, beyond the size necessary for fighting the insurrection, as a commitment to not reforming the military in the future. Keywords: civil wars, commitment, coups, military, political transitions, political economy. JEL Classifications: H2, N10, N40, P16.

We provide a model to investigate the tension between information aggregation and spread of misinformation in large societies (conceptualized as networks of agents communicating with each other). Each individual holds a belief represented by a scalar. Individuals meet pairwise and exchange information, which is modeled as both individuals adopting the average of their pre-meeting beliefs. When all individuals engage in this type of information exchange, the society will be able to effectively aggregate the initial information held by all individuals. There is also the possibility of misinformation, however, because some of the individuals are "forceful," meaning that they influence the beliefs of (some) of the other individuals they meet, but do not change their own opinion. The paper characterizes how the presence of forceful agents interferes with information aggregation. Under the assumption that even forceful agents obtain some information (however infrequent) from some others (and additional weak regularity conditions), we first show that beliefs in this class of societies converge to a consensus among all individuals. This consensus value is a random variable, however, and we characterize its behavior. Our main results quantify the extent of misinformation in the society by either providing bounds or exact results (in some special cases) on how far the consensus value can be from the benchmark without forceful agents (where there is efficient information aggregation). The worst outcomes obtain when there are several forceful agents and forceful agents themselves update their beliefs only on the basis of information they obtain from individuals most likely to have received their own information previously. Keywords: information aggregation, learning, misinformation, social networks. JEL Classifications: C72, D83.

We present a framework for understanding the effects of automation and other types of technological changes on labor demand, and use it to interpret changes in US employment over the recent past. At the center of our framework is the allocation of tasks to capital and labor--the task content of production. Automation, which enables capital to replace labor in tasks it was previously engaged in, shifts the task content of production against labor because of a displacement effect. As a result, automation always reduces the labor share in value added and may reduce labor demand even as it raises productivity. The effects of automation are counterbalanced by the creation of new tasks in which labor has a comparative advantage. The introduction of new tasks changes the task content of production in favor of labor because of a reinstatement effect, and always raises the labor share and labor demand. We show how the role of changes in the task content of production--due to automation and new tasks--can be inferred from industry-level data. Our empirical decomposition suggests that the slower growth of employment over the last three decades is accounted for by an acceleration in the displacement effect, especially in manufacturing, a weaker reinstatement effect, and slower growth of productivity than in previous decades.