Knowledge that Transforms

While condoms are an effective defense against the transmission of HIV, large numbers of sex workers are not using them. We argue that some sex workers are willing to take the risk because clients are willing to pay more to avoid using condoms. Using data from Mexico, we estimate that sex workers received a 23 percent premium for unprotected sex. The premium represents a value of one life year of between $14,760 and $51,832 or one to five times annual earnings. The premium jumped to 46 percent if the sex worker was considered very attractive, a measure of bargaining power.

We reconsider the identification and estimation of Gorman‐Lancaster‐style hedonic models of demand for differentiated products in the spirit of Sherwin Rosen. We generalize Rosen’s first stage to account for product characteristics that are not observed and to allow the hedonic pricing function to have a general nonseparable form. We take an alternative semiparametric approach to Rosen’s second stage in which we assume that the parametric form of utility is known, but we place no restrictions on the aggregate distribution of utility parameters. If there are only a small number of products, we show how to construct bounds on individuals’ utility parameters, as well as other economic objects such as aggregate demand and consumer surplus. We apply our methods to estimating the demand for personal computers.

The paper develops a theory of costly communication in which the sender’s and receiver’s motivations and abilities endogenously determine the communication mode and the transfer of knowledge. Communication is modeled as a problem of moral hazard in teams, in which the sender and receiver select persuasion and message elaboration efforts. The model is shown to provide a rich set of insights concerning (i) the impact of incentive alignment on communication strategies, (ii) the relative influence and the complementarity/substitutability between issue‐relevant communication and cues (information that relates to the credibility of the sender rather than to the issue at stake), and (iii) the path dependency of communication.

Great Lakes iron ore producers had faced no competition from foreign iron ore in the Great Lakes steel market for nearly a century as the 1970s closed. In the early 1980s, as a result of unprecedented developments in the world steel market, Brazilian producers were offering to deliver iron ore to Chicago (the heart of the Great Lakes market) at prices substantially below prices of local iron ore. The U.S. and Canadian iron ore industries faced a major crisis that cast doubt on their future. In response to the crisis, these industries dramatically increased productivity. Labor productivity doubled in a few years (whereas it had changed little in the preceding decade). Materials productivity increased by more than half. Capital productivity increased as well. I show that most of the productivity gains were due to changes in work practices. Work practice changes reduced overstaffing and hence increased labor productivity. By increasing the fraction of time equipment was in operating mode, changes in work practices also significantly increased materials and capital productivity.

People continue to live in many big American cities, because in those cities housing costs less than new construction. While cities may lose their productive edge, their houses remain and population falls only when housing depreciates. This paper presents a simple durable housing model of urban decline with several implications which document: (1) urban growth rates are leptokurtotic --cities grow more quickly than they decline, (2) city growth rates are highly persistent, especially amount declining cities,

In this paper we argue that the primary force behind the large drop in real exchange rates that occurs after large devaluations is the slow adjustment in the prices of nontradable goods and services. Our empirical analysis uses data from five large devaluation episodes: Argentina (2002), Brazil (1999), Korea (1997), Mexico (1994), and Thailand (1997). We conduct a detailed analysis of the Argentinian case using disaggregated consumer price index data, data from our own survey of prices in Buenos Aires, and scanner data from supermarkets. We assess the robustness of our findings by studying large real exchange rate appreciations, medium devaluations, and small exchange rate movements.

We evaluate the allocation of risk between firms and their workers using matched employer‐employee panel data. Unlike previous contributions, this paper focuses on idiosyncratic shocks to the firm, which are the correct empirical counterpart of the theoretical notion of diversifiable risk. We allow for both temporary and permanent shocks to output and find that firms absorb temporary fluctuations fully but insure workers against permanent shocks only partially. Risk‐sharing considerations can account for about 15 percent of overall earnings variability, the remainder originating from idiosyncratic shocks to individual workers. Our welfare calculations indicate that firms are an important vehicle of insurance provision.

We consider an economy that has to decide how assets are to be used. Agents have ideas, but these ideas conflict. We suppose that decision‐making authority is determined by hierarchy: each asset has a chain of command, and the most senior person with an idea exercises authority. We analyze the optimal hierarchical structure given that some agents coordinate and other specialize. Among other things, our theory explains why coordinators should typically be senior to specialists and why pyramidal hierarchies may be optimal. Our theory also throws light on the optimal degree of decentralization inside a firm and on firm boundaries.

Numerous design and repair services are nonstandard and have to be tailored to the needs of the individual buyers. Prospective sellers have to make preliminary efforts in order to come up with a plan, and buyers often consult a number of sellers before making a purchase. The literature on procurement studies such situations for the case of a large buyer who can commit to a procurement mechanism. The present paper considers the case of a small buyer who cannot commit to a mechanism. It develops a simple sequential procurement model and investigates its equilibria and welfare optima. The main qualitative conclusion concerns the inherent inefficiency of the equilibria. The price competition results in too low consultation fees, which induce overly intense search by buyers, which in turn erodes sellers’ effort incentives.

This paper evaluates the importance of "property rights institutions," which protect citizens against expropriation by the government and powerful elites, and "contracting institutions," which enable private contracts between citizens. We exploit exogenous variation in both types of institutions driven by colonial history and document strong first‐stage relationships between property rights institutions and the determinants of European colonization strategy (settler mortality and population density before colonization) and between contracting institutions and the identity of the colonizing power. Using this instrumental variables approach, we find that property rights institutions have a first‐order effect on long‐run economic growth, investment, and financial development. Contracting institutions appear to matter only for the form of financial intermediation. A possible explanation for this pattern is that individuals often find ways of altering the terms of their formal and informal contracts to avoid the adverse effects of weak contracting institutions but find it harder to mitigate the risk of expropriation in this way.