Knowledge that Transforms

The paper studies procurement contracts with pre-project investigations in the presence of adverse selection and moral hazard. To model the procurer's problem, we extend a standard sequential screening model to endogenous information acquisition with moral hazard. The optimal contract displays systematic distortions in information acquisition. Due to a rent effect, adverse selection induces too much information acquisition to prevent cost overruns and too little information acquisition to prevent false project cancellations. Moral hazard mitigates the distortions related to cost overruns yet exacerbates those related to false negatives. The optimal mechanism is a menu of option contracts that achieves the dual goal of providing incentives for information acquisition and truthful information revelation.

The higher legislative success of parliamentary governments relative to presidential governments has been used to argue that legislative success is driven by parliamentary governments' superior agenda power or their control of legislative majorities. We show that this approach is at odds with some of the empirical regularities across and within political systems. We then propose a legislative bargaining model to elucidate this puzzle. In the model, the policies of a confidence-dependent parliamentary government enjoy more predictable support from governing coalition members because their short-term policy goals are less important than the government's survival. Coalition support is stronger when the government has more agenda power and is weaker with a larger ruling coalition. We explore the empirical implications of these findings and their consequences for the comparative study of legislative institutions.

To analyse the role that the World Trade Organization (WTO) plays in enforcing international trade agreements, this paper first explores what countries can achieve alone by characterizing optimal private trigger strategies ( PTS ) under which each country triggers a punishment phase by imposing an explicit tariff based on privately observed imperfect signals of the other country's concealed trade barriers. It identifies the condition under which countries can restrain the use of concealed barriers based on PTS and establishes that countries will not reduce the cooperative protection level to its minimum attainable level under the optimal PTS . This paper then considers third-party trigger strategies ( TTS ) under which the WTO allows each country to initiate a punishment phase based on the WTO's judgement about potential violations. By comparing the optimal PTS and optimal TTS , it demonstrates that the WTO facilitates a better cooperative equilibrium by changing the nature of punishment-triggering signals from private to public , which in turn enables countries to use a more efficient punishment, such as an asymmetric and a minimum punishment.

This paper demonstrates the existence and robustness of partially revealing rational expectations equilibria in general exchange economies when some traders have non-smooth ambiguity-averse preferences. This finding illustrates that models with non-smooth ambiguity aversion provide a relatively tractable framework through which partial information revelation may be studied in a general equilibrium setting without relying on particular distributional or von Neumann–Morgenstern utility assumptions or the presence of “noise.”

We study the (perfect Bayesian) equilibrium of a sequential learning model over a general social network. Each individual receives a signal about the underlying state of the world, observes the past actions of a stochastically generated neighbourhood of individuals, and chooses one of two possible actions. The stochastic process generating the neighbourhoods defines the network topology. We characterize pure strategy equilibria for arbitrary stochastic and deterministic social networks and characterize the conditions under which there will be asymptotic learning—convergence (in probability) to the right action as the social network becomes large. We show that when private beliefs are unbounded (meaning that the implied likelihood ratios are unbounded), there will be asymptotic learning as long as there is some minimal amount of “expansion in observations”. We also characterize conditions under which there will be asymptotic learning when private beliefs are bounded.

This paper provides a new, empirically driven application of the dynamic Mirrleesian framework by studying a feasible and potentially powerful tax reform: age-dependent labour income taxation. I show analytically how age dependence improves policy on both the intratemporal and intertemporal margins. I use detailed numerical simulations, calibrated with data from the U.S. Panel Study of Income Dynamics, to generate robust policy implications: age dependence (1) lowers marginal taxes on average and especially on high-income young workers and (2) lowers average taxes on all young workers relative to older workers when private saving and borrowing are restricted. Finally, I calculate and characterize the welfare gains from age dependence. Despite its simplicity, age dependence generates a welfare gain equal to between 0·6% and 1·5% of aggregate annual consumption, and it captures more than 60% of the gain from reform to the dynamic optimal policy. The gains are due to substantial increases in both efficiency and equity. When age dependence is restricted to be Pareto improving, the welfare gain is nearly as large.

In this paper, I examine ε-equilibria of stationary dynamic economies with heterogeneous agents and possibly incomplete financial markets. I give a simple example to show that even for arbitrarily small ε > 0, allocation and prices can be far away from exact equilibrium allocations and prices. That is, errors in market clearing or individuals' optimality conditions do not provide enough information to assess the quality of an approximation. I derive a sufficient condition for an ε-equilibrium to be close to an exact equilibrium. If the economic fundamentals are semi-algebraic, one can verify computationally whether this condition holds. The condition can be interpreted economically as a robustness requirement on the set of ε-equilibria which form a neighbourhood of the computed approximation. I illustrate the main result and the computational method using an infinite horizon economy with overlapping generations and incomplete financial markets.

Which decision rules are the most efficient? Which are the best in terms of maximin or maximax? We study these questions for the case of a group of individuals faced with a collective choice from a set of alternatives. A key message from our results is that the set of optimal decision rules is well defined, particularly simple, and well known: the class of scoring rules. We provide the optimal scoring rules for the three different ideals of justice under consideration: utilitarianism (efficiency), maximin, and maximax. The optimal utilitarian scoring rule depends crucially on the probability distribution of the utilities. The optimal maximin (respectively maximax) scoring rule takes the optimal utilitarian scoring rule and applies a factor that shifts it towards negative voting (respectively plurality voting).

We develop a theory of media slant as a systematic filtering of political news that reduces multidimensional politics to the one-dimensional space perceived by voters. Economic and political choices are interdependent in our theory: expected electoral results influence economic choices, and economic choices in turn influence voting behaviour. In a two-candidate election, we show that media favouring the front-runner will focus on issues unlikely to deliver a surprise, while media favouring the underdog will gamble for resurrection. We characterize the socially optimal slant and show that it coincides with the one favoured by the underdog under a variety of circumstances. Balanced media, giving each issue equal coverage, may be worse for voters than partisan media.

This paper estimates the effect of the early childhood environment on a large array of social and economic outcomes lasting almost 60 years. To do this, we exploit variation in the living conditions experienced by Yemenite children after being airlifted to Israel in 1949. We find that children who were placed in a more modern environment ( i.e. with better sanitary and infrastructure conditions) were more likely to obtain higher education, marry at an older age, have fewer children, and work at age 55. They were also more likely to be assimilated into Israeli society, to be less religious, and have more worldly tastes in music and food. However, these effects are found mainly for women and not for men. We also find an effect on the next generation—children who lived in a better environment grew up to have children with more education.