Knowledge that Transforms

This paper develops and estimates an equilibrium model where heterogeneous firms can exploit two margins of informality: (i) not register their business, the extensive margin; and (ii) hire workers “off the books,” the intensive margin. The model encompasses the main competing frameworks for understanding informality and provides a natural setting to infer their empirical relevance. The counterfactual analysis shows that once the intensive margin is accounted for, firm and labor informality need not move in the same direction as a result of policy changes. Lower informality can be, but is not necessarily associated with higher output, TFP, or welfare. (JEL D22, E26, H26, J46, O14, O17)

We survey New Zealand firms and document novel facts about their macroeconomic beliefs. There is widespread dispersion in beliefs about past and future macroeconomic conditions, especially inflation. This dispersion in beliefs is consistent with firms’ incentives to collect and process information. Using experimental methods, we find that firms update their beliefs in a Bayesian manner when presented with new information about the economy and that changes in their beliefs affect their decisions. Inflation is not generally perceived as being important to business decisions so firms devote few resources to collecting and processing information about inflation. (JEL D22, D83, D84, E31, E52)

I conducted a randomized field experiment in traditional public elementary schools in Houston, Texas designed to test the potential productivity benefits of teacher specialization. The average impact of encouraging schools to specialize their teachers on student achievement is −0.11 standard deviations per year on a combined index of math and reading test scores. I argue that the results are consistent with a model in which the benefits of specialization driven by sorting teachers into a subset of subjects based on comparative advantage is outweighed by inefficient pedagogy due to having fewer interactions with each student, though other mechanisms are possible. (JEL D31, E32, J22, J24, J31)

This paper studies the impact of unemployment insurance (UI) on the housing market. Exploiting heterogeneity in UI generosity across US states and over time, we find that UI helps the unemployed avoid mortgage default. We estimate that UI expansions during the Great Recession prevented more than 1.3 million foreclosures and insulated home values from labor market shocks. The results suggest that policies that make mortgages more affordable can reduce foreclosures even when borrowers are severely underwater. An optimal UI policy during housing downturns would weigh, among other benefits and costs, the deadweight losses avoided from preventing mortgage defaults. (JEL D14, E32, G21, J65, R31)

More than one-half of all people living with HIV are women and 80 percent of all HIV-positive women in the world live in sub- Saharan Africa. This paper demonstrates that the legal origins of these formerly colonized countries significantly determine current-day female HIV rates. In particular, female HIV rates are significantly higher in common law sub- Saharan African countries compared to civil law ones. This paper explains this relationship by focusing on differences in female property rights under the two codes of law. In sub- Saharan Africa, common law is associated with weaker female marital property laws. As a result, women in these common law countries have lower bargaining power within the household and are less able to negotiate safe sex practices and are thus more vulnerable to HIV, compared to their civil law counterparts. Exploiting the fact that some ethnic groups in sub- Saharan Africa cross country borders with different legal systems, we are able to include ethnicity fixed effects into a regression discontinuity approach. This allows us to control for a large set of cultural, geographical, and environmental factors that could be confounding the estimates. The results of this paper are consistent with gender inequality (the "feminization" of AIDS), explaining much of its prevalence in sub- Saharan Africa.

We document the evolution of the new market for frequency response within the UK electricity system over a six-year period. Firms competed in price while facing considerable initial uncertainty about demand and rival behavior. We show that prices stabilized over time, converging to a rest point that is consistent with equilibrium play. We draw on models of fictitious play and adaptive learning to analyze how this convergence occurs and show that these models predict behavior better than an equilibrium model prior to convergence. (JEL D22, D83, L13, L94, L98)

We examine the impact of mismatch on entry wages, separations, and wage growth using unique data on worker talents. We show that workers are sorted on comparative advantage across jobs within occupations. The starting wages of inexperienced workers are unrelated to mismatch. For experienced workers, on the other hand, mismatch is negatively priced into their starting wages. Separations and wage growth are more strongly related to mismatch among inexperienced workers than among experienced workers. These findings are consistent with models of information updating, where less information is available about the quality of matches involving inexperienced workers. (JEL D83, J24, J31, J41, J63, J64)

This paper examines the relationship between the destination of exports and the input prices paid by firms, using detailed customs and firm-product-level data from Portugal. Both ordinary least squares regressions and an instrumental-variable strategy using exchange-rate movements (interacted with indicators for initial exports) as a source of variation in destinations indicate that exporting to richer countries leads firms to pay higher prices for inputs, other things equal. The results are supportive of what we call the income-based quality-choice channel: selling to richer destinations leads firms to raise the average quality of goods they produce and to purchase higher-quality inputs. (JEL D22, D24, F14, F31, L15)

We propose a technique for assessing robustness to demand effects of findings from experiments and surveys. The core idea is that by deliberately inducing demand in a structured way we can bound its influence. We present a model in which participants respond to their beliefs about the researcher’s objectives. Bounds are obtained by manipulating those beliefs with “demand treatments.” We apply the method to 11 classic tasks, and estimate bounds averaging 0.13 standard deviations, suggesting that typical demand effects are probably modest. We also show how to compute demand-robust treatment effects and how to structurally estimate the model. (JEL C83, C90, D83, D91)

Marketplaces are often small parts of large markets, and both markets and marketplaces come in many varieties. Market design seeks to understand what marketplaces must accomplish to enable different kinds of markets. Marketplaces can have varying degrees of success, and there can be marketplace failures. I’ll discuss labor markets like the market for new economists, and also markets for new lawyers and doctors that have suffered from the unraveling of appointment dates to well before employment begins. Markets work best if they enjoy social support, but some markets are repugnant in the sense that some people think they should be banned, even though others want to participate in them. Laws banning such markets often contribute to the design of illegal black markets, and this raises new issues for market designers. I’ll briefly discuss markets and black markets for narcotics, marijuana, sex, and surrogacy, and the design of markets for kidney transplants, in the face of widespread laws against (and broader repugnance for) compensating organ donors. I conclude with open questions and engineering challenges.