Knowledge that Transforms

To what extent can an incumbent manufacturer use discount contracts to foreclose efficient entry? We show that off-list-price rebates that do not commit buyers to unconditional transfers—like the rebates in EU Commission v. Michelin II, for instance—cannot be anticompetitive. This is true even in the presence of cost uncertainty, scale economies, or intense downstream competition, all three market settings where exclusion has been shown to emerge with exclusive dealing contracts. The difference stems from the fact that, unlike exclusive dealing provisions, rebates do not contractually commit retailers to exclusivity when signing the contract. (JEL D43, D86, K21, L13, L14, L42, L60)

We model an online display advertising environment in which “performance” advertisers can measure the value of individual impressions, whereas “brand” advertisers cannot. If advertiser values for ad opportunities are positively correlated, second-price auctions for impressions can be inefficient and expose brand advertisers to adverse selection. Bayesian-optimal auctions have other drawbacks: they are complex, introduce incentives for false-name bidding, and do not resolve adverse selection. We introduce “modified second bid” auctions as the unique auctions that overcome these disadvantages. When advertiser match values are drawn independently from heavy-tailed distributions, a modified second bid auction captures at least 94.8 percent of the first-best expected value. In that setting and similar ones, the benefits of switching from an ordinary second-price auction to the modified second bid auction may be large, and the cost of defending against shill bidding and adverse selection may be low. (JEL D44, D82, L86, M37)

From 1980 to 2000, the rise in the US college/high school graduate wage gap coincided with increased geographic sorting as college graduates concentrated in high wage, high rent cities. This paper estimates a structural spatial equilibrium model to determine causes and welfare consequences of this increased skill sorting. While local labor demand changes fundamentally caused the increased skill sorting, it was further fueled by endogenous increases in amenities within higher skill cities. Changes in cities' wages, rents, and endogenous amenities increased inequality between high school and college graduates by more than suggested by the increase in the college wage gap alone. (JEL D31, I26, J24, J31, J61, R23)

We study decentralized mechanisms for allocating firms into search pools. The pools are created in response to noisy preference signals provided by consumers, who then browse the pools via costly random sequential search. Surplus-maximizing search pools are implementable in symmetric Nash equilibrium. Full extraction of the maximal surplus is implementable if and only if the distribution of consumer types satisfies a set of simple inequalities, which involve the relative fractions of consumers who like different products and the Bhattacharyya coefficient of similarity between their conditional signal distributions. The optimal mechanism can be simulated by a keyword auction with broad matching. (JEL C78, D44, D82)

When an agent chooses between prospects, noise in information processing generates an effect akin to the winner's curse. Statistically unbiased perception systematically overvalues the chosen action because it fails to account for the possibility that noise is responsible for making the preferred action appear to be optimal. The optimal perception pattern exhibits a key feature of prospect theory, namely, overweighting of small probability events (and corresponding underweighting of high probability events). This bias arises to correct for the winner's curse effect. (JEL D11, D81, D82, D83)

Administrative income tax data indicate that U.S. top income and wealth shares are both substantial and larger than shares observed in household surveys. However, these estimates are sensitive to the unit of analysis, the income concept measured in tax records, and, in the case of wealth, to assumptions about the correlation between income and wealth. We constrain a household survey--the Survey of Consumer Finances--to be conceptually comparable to tax records and are able to reconcile the much of the difference between the survey and administrative estimates. Wealth estimates from administrative income tax data are sensitive to model parameters.

Women are underrepresented in science and engineering, with the underrepresentation increasing in career stage. We analyze gender differences at critical junctures in the STEM pathway--graduate training and the early career--using UMETRICS administrative data matched to the 2010 Census and W-2s. We find strong gender separation in teams, although the effects of this are ambiguous. While no clear disadvantages exist in training environments, women earn 10% less than men once we include a wide range of controls, most notably field of study. This gap disappears once we control for women's marital status and presence of children.

A common view is that bailouts of firms by governments are needed to cure inefficiencies in private markets. We propose an alternative view: even when private markets are efficient, costly bankruptcies will occur and benevolent governments without commitment will bail out firms to avoid bankruptcy costs. Bailouts then introduce inefficiencies where none had existed. Although granting the government orderly resolution powers which allow it to rewrite private contracts improves on bailout outcomes, regulating leverage and taxing size is needed to achieve the relevant constrained efficient outcome, the sustainably efficient outcome. This outcome respects governments' incentives to intervene when they lack commitment. (JEL D86, E32, G33, H81, L51)

We develop a dynamic multicountry general equilibrium model to investigate forces acting on the global economy during the Great Recession and ensuing recovery. Our multisector framework accounts completely for countries' trade, investment, production, and GDPs in terms of different sets of shocks. Applying the model to 21 countries, we investigate the 29 percent drop in world trade in manufactures during the period 2008–2009. A shift in final spending away from tradable sectors, largely caused by declines in durables investment efficiency, accounts for most of the collapse in trade relative to GDP. Shocks to trade frictions, productivity, and demand play minor roles. (JEL E3, F1, F4)

We document that women are less represented on corporate boards in Finance and more traditional STEM industry sectors. Even after controlling for differences in firm and country characteristics, average diversity in these sectors is 24% lower than the mean. Our findings suggest that well-documented gender differences in STEM university enrolments and occupations have long-term consequences for female business leadership. The leadership gap in Finance and STEM may be difficult to eliminate using blanket boardroom diversity policies. Diversity policies are also likely to have a different impact on firms in these sectors than in non-STEM sectors.