We propose a simple theoretical model of supervised learning that is potentially useful to interpret a number of empirical phenomena relevant to the nature-nurture debate. The model captures a basic trade-off between sheltering the child from the consequences of his mistakes and allowing him to learn from experience. We characterize the optimal parenting policy and its comparative-statics properties. We then show that key features of the optimal policy can be useful to interpret provocative findings from behavioral genetics.

We present a dynamic model of adverse selection to examine the interactions between new and used goods markets. We find that the used market never shuts down, the volume of trade can be large, and distortions are lower than previously thought. New cars prices can be higher under adverse selection than in its absence. An extension to several brands that differ in reliability leads to testable predictions of the effects of adverse selection. Unreliable brands have steeper price declines and lower volumes of trade. We contrast these predictions with those of a model where brands physically depreciate at different rates. (JEL D82, L15)

Leasing contracts are extensively used in durable goods markets. These contracts specify a rental rate and an option price at which the used good can be bought on termination of the lease. This option price cannot be controlled when the car is sold. We show that in a world in which quality is observable, this additional control variable is ineffective. Under adverse selection instead, leasing contracts affect equilibrium allocations in a way that matches observed behavior in the car market. Consistent with the data, our model predicts that leased cars have a higher turnover and that off‐lease used cars are of higher quality. Moreover, the model predicts that the recent increase in leasing can be explained by the observed increase in car durability. We show that leasing contracts can improve welfare but that they are imperfect tools. We also show that a producer with market power can benefit from leasing contracts for two reasons: market segmentation and better pricing of the option. Moreover, despite the fact that lessors could structure contracts to prevent adverse selection, we show that this is not in their interest.

We discuss a class of markets for durable goods where efficiency (or approximate efficiency) is obtained despite the presence of information asymmetries. In the model, the number of times a good has changed hands (the vintage of the good) is an accurate signal of its quality, each consumer self-selects into obtaining the vintage that the social planner would have assigned to her, and consumers' equilibrium trading behaviour in secondary markets is not subject to adverse selection. We show that producers have the incentive to choose contracts that lead to the efficient allocation, and to supply the efficient output. We also provide a contrast between leasing contracts, resale contracts, and different kinds of rental contracts. Resale contracts do not lead to the efficient allocation. A specific kind of rental contract provides the appropriate incentives to consumers.

Does the Secondary Life Insurance Market Threaten Dynamic Insurance? by Glenn Daily, Igal Hendel and Alessandro Lizzeri. Published in volume 98, issue 2, pages 151-56 of American Economic Review, May 2008

We study dynamic monopoly pricing of storable goods in an environment where demand changes over time. The literature on durables has focused on incentives to delay purchases. Our analysis focuses on a different intertemporal demand incentive. The key force on the consumer side is advance purchases or stockpiling. In the case of storable goods, the stockpiling motive has recently been documented empirically. We show that, in this environment, if the monopolist cannot commit, then prices are higher in all periods, and social welfare is lower, than in the case in which the monopolist can commit. This is in contrast with the analysis in the literature on the Coase conjecture.

We provide a two period model of political competition in which voters imperfectly observe the electoral promises made to other voters. Imperfect observability generates an incentive for candidates to offer excessive transfers even if voters are homogeneous and taxation is distortionary. Government spending is larger than in a world of perfect observability. Transfers are partly financed through government debt, and the size of the debt is higher in less transparent political systems. The model provides an explanation of fiscal churning; it also predicts that groups whose transfers are less visible to others receive higher transfers, and that imperfect transparency of transfers may lead to underprovision of public goods. From the policy perspective, the main novelty of our analysis is a separate evaluation of the transparency of spending and the transparency of revenues. We show that the transparency of the political system does not unambiguously improve efficiency: transparency of spending is beneficial, but transparency of revenues can be counterproductive because it endogenously leads to increased wasteful spending.

Many countries have recently enacted or proposed reforms aimed at increasing citizens’ information on the quality of some public sector services. Disclosure of schools’and teachers’ quality is the case that has generated the biggest public debate. In the US, the No Child Left Behind Act (NCLB) requires learning progress to be measured for every child and results from students’tests be made available in annual report cards, so that parents can evaluate schools’ performances. Similar reforms have also been proposed for many other public services. In the UK, legislation introduced in the year 2000 now requires that the performance of each Local Government is reviewed and made public with regards to provision of services such as …re, police, housing, social services and education, but also like the condition of roads, the average time taken to remove ‡y-tips and the amount of household waste recycled. 1 By and large, most of these reforms have been opposed by the public sector employees a¤ected. In the US, the largest teachers union- the National Education Association- spent more than $8 million in an e¤ort to derail NCLB. In the UK, public service unions greeted reforms with increased scepticism and ultimately hostility. More generally, it is di ¢ cult to …nd groups of public sector workers or trade unions lobbying the government to disclose more information about quality. Moreover, in contrast with the private sector, it is much less common to see even the highest quality providers (hospitals, schools,....) trying to

Politicians who care about the spoils of office may underprovide a public good because its benefits cannot be targeted to voters as easily as pork-barrel spending. We compare a winner-take-all system—where all the spoils go to the winner—to a proportional system—where the spoils of office are split among candidates proportionally to their share of the vote. In a winner-take-all system the public good is provided less often than in a proportional system when the public good is particularly desirable. We then consider the electoral college system and show that it is particularly subject to this inefficiency. (JEL D82, L15)

Abstract This article presents a dynamic political-economic model of total government obligations. Its focus is on the interplay between debt and entitlements. In our model, both are tools by which temporarily powerful groups can extract resources from groups that will be powerful in the future: debt transfers resources across periods; entitlements directly target the future allocation of resources. We prove the following results. First, the presence of endogenous entitlements dampens the incentives of politically powerful groups to accumulate debt, but it leads to an increase in total government obligations. Second, fiscal rules can have perverse effects: if entitlements are unconstrained, and there are capital market frictions, debt limits lead to an increase in total government obligations and to worse outcomes for all groups. Analogous results hold for entitlement limits. Third, our model sheds some lights on the influence of capital market frictions on the incentives of governments to adopt fiscal rules, and implement entitlement programs. Finally, we identify preference polarization as a possible explanation for the joint growth of debt and entitlements.