We study the formation of a ruling coalition in non-democratic societies where institutions do not enable political commitments. Each individual is endowed with a level of political power. The ruling coalition consists of a subset of the individuals in the society and decides the distribution of resources. A ruling coalition needs to contain enough powerful members to win against any alternative coalition that may challenge it, and it needs to be self-enforcing, in the sense that none of its subcoalitions should be able to secede and become the new ruling coalition. We present both an axiomatic approach that captures these notions and determines a (generically) unique ruling coalition and the analysis of a dynamic game of coalition formation that encompasses these ideas. We establish that the subgame-perfect equilibria of the coalition formation game coincide with the set of ruling coalitions resulting from the axiomatic approach. A key insight of our analysis is that a coalition is made self-enforcing by the failure of its winning subcoalitions to be self-enforcing. This is most simply illustrated by the following example: with “majority rule”, two-person coalitions are generically not self-enforcing and consequently, three-person coalitions are self-enforcing (unless one player is disproportionately powerful). We also characterize the structure of ruling coalitions. For example, we determine the conditions under which ruling coalitions are robust to small changes in the distribution of power and when they are fragile. We also show that when the distribution of power across individuals is relatively equal and there is majoritarian voting, only certain sizes of coalitions (e.g. with majority rule, coalitions of size 1, 3, 7, 15, etc.) can be the ruling coalition.

The announcement of Timothy Geithner as nominee for Treasury Secretary in November 2008 produced a cumulative abnormal return for financial firms with which he had a prior connection. This return was about 6% after the first full day of trading and about 12% after ten trading days. There were subsequently abnormal negative returns for connected firms when news broke that Geithner’s confirmation might be derailed by tax issues. Personal connections to top executive branch officials can matter greatly even in a country with strong overall institutions, at least during a time of acute financial crisis and heightened policy discretion.

We study the direct and spillover effects of local state capacity in Colombia. We model the determination of state capacity as a network game between municipalities and the national government. We estimate this model exploiting the municipality network and the roots of local state capacity related to the presence of the colonial state and royal roads. Our estimates indicate that local state capacity decisions are strategic complements. Spillover effects are sizable, accounting for about 50 percent of the quantitative impact of an expansion in local state capacity, but network effects driven by equilibrium responses of other municipalities are much larger.

This paper introduces endogenous and directed technical change in a growth model with environmental constraints and limited resources. A unique final good is produced by combining inputs from two sectors. One of these sectors uses "dirty" machines and thus creates environmental degradation. Research can be directed to improving the technology of machines in either sector. We characterize dynamic tax policies that achieve sustainable growth or maximize intertemporal welfare, as a function of the degree of substitutability between clean and dirty inputs, environmental and resource stocks, and cross-country technological spillovers. We show that: (i) in the case where the inputs are sufficiently substitutable, sustainable long-run growth can be achieved with temporary taxation of dirty innovation and production; (ii) optimal policy involves both "carbon taxes" and research subsidies, so that excessive use of carbon taxes is avoided; (iii) delay in intervention is costly: the sooner and the stronger is the policy response, the shorter is the slow growth transition phase; (iv) the use of an exhaustible resource in dirty input production helps the switch to clean innovation under laissez-faire when the two inputs are substitutes. Under reasonable parameter values (corresponding to those used in existing models with exogenous technology) and with sufficient substitutability between inputs, it is optimal to redirect technical change towards clean technologies immediately and optimal environmental regulation need not reduce long-run growth. We also show that in a two-country extension, even though optimal environmental policy involves global policy coordination, when the two inputs are sufficiently substitutable environmental regulation only in the North may be sufficient to avoid a global disaster.

An influential thesis often associated with de Tocqueville views social mobility as a bulwark of democracy: when members of a social group expect to join the ranks of other social groups in the near future, they should have less reason to exclude these other groups from the political process. In this article, we investigate this hypothesis using a dynamic model of political economy. As well as formalizing this argument, our model demonstrates its limits, elucidating a robust theoretical force making democracy less stable in societies with high social mobility: when the median voter expects to move up (respectively down), she would prefer to give less voice to poorer (respectively richer) social groups. Our theoretical analysis shows that in the presence of social mobility, the political preferences of an individual depend on the potentially conflicting preferences of her “future selves,” and that the evolution of institutions is determined through the implicit interaction between occupants of the same social niche at different points in time.

When voters fear that politicians may be influenced or corrupted by the rich elite, signals of integrity are valuable. As a consequence, an honest politician seeking reelection chooses “populist” policies—that is, policies to the left of the median voter—as a way of signaling that he is not beholden to the interests of the right. Politicians that are influenced by right-wing special interests respond by choosing moderate or even left-of-center policies. This populist bias of policy is greater when the value of remaining in office is higher for the politician; when there is greater polarization between the policy preferences of the median voter and right-wing special interests; when politicians are perceived as more likely to be corrupt; when there is an intermediate amount of noise in the information that voters receive; when politicians are more forward-looking; and when there is greater uncertainty about the type of the incumbent. We also show that soft term limits may exacerbate, rather than reduce, the populist bias of policies.

Health expenditures as a share of GDP in the United States have more than tripled over the past half-century. A common conjecture is that this is a consequence of rising income. We investigate this hypothesis by instrumenting for local area income with time series variation in oil prices interacted with local oil reserves. This strategy enables us to capture both partial equilibrium and local general equilibrium effects of income on health expenditures. Our central income elasticity estimate is 0.7, with 1.1 as the upper end of the 95% confidence interval, which suggests that rising income is unlikely to be a major driver of the rising health expenditure share of GDP.

In dynamic collective decision making, current decisions determine the future distribution of political power and influence future decisions. We develop a general framework to study this class of problems. Under acyclicity, we characterize dynamically stable states as functions of the initial state and obtain two general insights. First, a social arrangement is made stable by the instability of alternative arrangements that are preferred by sufficiently powerful groups. Second, efficiency-enhancing changes may be resisted because of further changes they will engender. We use this framework to analyze dynamics of political rights in a society with different types of extremist views.

January 2009Although almost half of the world™s population lives under nondemocratic regimes, thequestions of how policy decisions are made and how power changes hands in nondemocra-cies have received relatively little attention in the political economy literature. A popularview, forcefully articulated by Gordon Tullock (1987), is that because there are no stronginstitutions ensuring consensus and regulating the election and succession of leaders, non-democratic regimes rapidly degenerate into personal rule, where a single dictator dominatesevery aspect of decision-making. Tullock writes: fiEmpirically the Junta characteristicallyshrinks to one man...fl(p. 144) and continues to explain this as the result of dynamic in-teractions among the members of the junta. He suggests that there will typically be anaccumulation of power by one of the junta members. If this upstart member succeeds, hebecomes the sole ruler. If he fails, he is eliminated by the other members of the junta.This process continues until one member is standing. Tullock thus concludes: fiIt can beseen that this process would tend over time to lead the junta into becoming just one manthrough the gradual exclusion of individuals who had failed in plotting or the success of anindividual who had not.fl(p. 145)Tullock™s account, like that of many others, implicitly recognizes that politics in non-democratic and weakly-institutionalized societies should be conceptualized as one of thedynamic coalition formationS there are no rules that ensure orderly transitions of powerand no checks against some members of the ruling coalition eliminating or sidelining others.However, formal models of dynamic coalition formation in nondemocratic societies have notbeen developed until recently.In this paper, we draw on our work on dynamic coalition formation (Daron Acemoglu,Georgy Egorov and Konstantin Sonin, 2008a) and investigate Tullock™s conjecture formally.1

The rise of Western Europe after 1500 is due largely to growth in countries with access to the Atlantic Ocean and with substantial trade with the New World, Africa, and Asia via the Atlantic. This trade and the associated colonialism affected Europe not only directly, but also indirectly by inducing institutional change. Where “initial” political institutions (those established before 1500) placed significant checks on the monarchy, the growth of Atlantic trade strengthened merchant groups by constraining the power of the monarchy, and helped merchants obtain changes in institutions to protect property rights. These changes were central to subsequent economic growth.