Knowledge that Transforms

Decentralization can improve service delivery, but it can also generate externalities across jurisdictional boundaries. We examine the nature and size of water pollution externalities as rivers flow across jurisdictions. Panel data on water pollution in Brazilian rivers coupled with county splits that change the locations of borders allow us to identify the spatial patterns of pollution as rivers approach and cross borders, controlling for fixed effects and trends specific to each location. The theory of externalities predicts that pollution should increase at an increasing rate as the river approaches the downstream exit border, that there should be a structural break in the slope of the pollution function at the border, and that a larger number of managing jurisdictions should exacerbate pollution externalities. We find support for all four predictions in the data. Satellite data on growth in night-time lights along rivers show that local authorities allow more settlements to develop close to rivers in the downstream portions of counties, which is the likely underlying mechanism. The border effects on pollution are not as pronounced when the cost of inter-jurisdictional coordination is lower.

In this article, we provide a model of the macroeconomic implications of safe asset shortages. In particular, we discuss the emergence of a deflationary safety trap equilibrium with endogenous risk premia. It is an acute form of a liquidity trap, in which the shortage of a specific form of assets, safe assets, as opposed to a general shortage of assets, is the fundamental driving force. At the Zero Lower Bound, our model has a Keynesian cross representation, in which net safe asset supply plays the role of an aggregate demand shifter. Essentially, safety traps correspond to liquidity traps in which the emergence of an endogenous risk premium significantly alters the connection between macroeconomic policy and economic activity. “Helicopter drops” of money, safe public debt issuances, swaps of private risky assets for safe public debt, or increases in the inflation target, stimulate aggregate demand and output, while forward guidance is less effective. The safety trap can be arbitrarily persistent, as in the secular stagnation hypothesis, despite the existence of infinitely lived assets.

We explore subjective performance reviews in long-term employment relationships. We show that firms benefit from separating the task of evaluating the worker from the task of paying him. The separation allows the reviewer to better manage the review process, and can, therefore, reward the worker for his good performance with not only a good review contemporaneously, but also a promise of better review in the future. Such reviews spread the reward for the worker’s good performance across time and lower the firm’s maximal temptation to renege on the reward. The manner in which information is managed exhibits patterns consistent with a number of well-documented biases in performance reviews.

A monetary authority can be committed to pursuing an inflation, price-level, or nominal-GDP target, yet systematically fail to achieve the prescribed goal. Constrained by the zero lower bound on the policy rate, the monetary authority is unable to implement its objectives when private sector expectations stray far enough from the target. Low-inflation expectations become self-fulfilling, resulting in an additional Markov equilibrium in which the monetary authority falls short of the nominal target, average output is below its efficient level, and the policy rate is typically low. Introducing a stabilization goal for long-term nominal rates can implement a unique Markov equilibrium without fully compromising stabilization policy.

Many health care treatments are not urgent and may be delayed if patients so choose. Because insurance coverage is typically determined by the treatment date, individuals may have incentives to strategically delay treatments to minimize out-of-pocket costs. The strategic delay of treatment—a particular form of moral hazard—can be an important source of subsequent adverse selection, in which ex ante identical individuals select insurance coverage based on their differing accumulation of previously delayed treatments. This article investigates these forces empirically in the context of the missing market for dental insurance. Using rich claim-level data, my analysis reveals that approximately 40% of individuals strategically delay dental treatments when incentivized to do so, and this flexibility in delaying treatment can explain why the market for dental insurance has largely unraveled. More generally, the counterfactual analysis suggests features such as open enrolment periods and contracting on pre-existing conditions may be helpful tools in overcoming adverse selection in insurance contexts where the timing of uncertainty is not contractible.

We analyse conditions facilitating profitable deception in a simple model of a competitive retail market. Firms selling homogenous products set anticipated prices that consumers understand and additional prices that naive consumers ignore unless revealed to them by a firm, where we assume that there is a binding floor on the anticipated prices. Our main results establish that “bad” products (those with lower social surplus than an alternative) tend to be more reliably profitable than “good” products. Specifically, (1) in a market with a single socially valuable product and sufficiently many firms, a deceptive equilibrium—in which firms hide additional prices—does not exist and firms make zero profits. But perversely, (2) if the product is socially wasteful, then a profitable deceptive equilibrium always exists. Furthermore, (3) in a market with multiple products, since a superior product both diverts sophisticated consumers and renders an inferior product socially wasteful in comparison, it guarantees that firms can profitably sell the inferior product by deceiving consumers. We apply our framework to the mutual fund and credit card markets, arguing that it explains a number of empirical findings regarding these industries.

This article performs a welfare analysis of markets with private information in which agents condition on prices in the rational expectations tradition. Price-contingent strategies introduce two externalities in the use of private information: a pecuniary externality and a learning externality. The pecuniary externality induces agents to put too much weight on private information and in the standard case, when the allocation role of the price prevails over its informational role, overwhelms the learning externality which impinges in the opposite way. The price may be very informative but at the cost of an excessive dispersion of the actions of agents. The welfare loss at the market solution may be increasing in the precision of private information. The analysis provides insights into optimal business cycle policy and a rationale for a Tobin-like tax for financial transactions.

We analyse a consumption-saving problem in which time-inconsistent preferences generate demand for commitment, but uncertainty about future consumption needs generates demand for flexibility. We characterize in a standard contracting framework the circumstances under which this combination is possible, in the sense that a commitment contract exists that implements the desired state-contingent consumption plan, thus offering both commitment and flexibility. The key condition that we identify is a preference reversal condition: high desired consumption today should be associated with low marginal utility at future dates. Moreover, there are conditions under which preference reversal naturally arises. The key insight of our article is that time-inconsistent preferences not only generate commitment problems, but also allow their possible solution, since the preferences of later selves can be exploited to punish overconsumption by earlier selves.

This article analyses the existence and the effects of bubbles in an endogenous growth model with financial frictions and heterogeneous investments. Bubbles are likely to emerge when the degree of pledgeability is in the middle range, implying that improving the financial market might increase the potential for asset bubbles. Moreover, when the degree of pledgeability is relatively low, bubbles boost long-run growth; when it is relatively high, bubbles lower growth. Furthermore, we examine the effects of a bubble burst, and show that the effects depend on the degree of pledgeability, that is, the quality of the financial system. Finally, we conduct a full welfare analysis of asset bubbles.

Assessing the importance of uninsurable wage risk for individual financial choices faces two challenges. First, the identification of the marginal effect requires a measure of at least one component of risk that cannot be diversified or avoided. Moreover, measures of uninsurable wage risk must vary over time to eliminate unobserved heterogeneity. Second, evaluating the economic significance of risk requires knowledge of the size of all the wage risk actually faced. Existing estimates are problematic because measures of wage risk fail to satisfy the "non-avoidability" requirement. This creates a downward bias which is at the root of the small estimated effect of wage risk on portfolio choices. To tackle this problem we match panel data of workers and firms and use the variability in the profitability of the firm that is passed over to workers to obtain a measure of uninsurable risk. Using this measure to instrument total variability in individual earnings, we find that the marginal effect of uninsurable wage risk is much larger than estimates that ignore endogeneity. We bound the economic impact of risk and find that its overall effect is contained, not because its marginal effect is small but because its size is small. And the size of uninsurable wage risk is small because firms provide substantial wage insurance.