Industry dynamics: Foundations for models with an infinite number of firms

This paper explores the connection between three important threads of economic research offering different approaches to studying the dynamics of an industry with heterogeneous firms. Finite models of the form pioneered by Ericson and Pakes (1995) capture the dynamics of a finite number of heterogeneous firms as they compete in an industry, and are typically analyzed using the concept of Markov perfect equilibrium (MPE). Infinite models of the form pioneered by Hopenhayn (1992), on the other hand, consider an infinite number of infinitesimal firms, and are typically analyzed using the concept of stationary equilibrium (SE). A third approach uses oblivious equilibrium (OE), which maintains the simplifying benefits of an infinite model but within the more realistic setting of a finite model. The paper relates these three approaches. The main result of the paper provides conditions under which SE of infinite models approximate MPE of finite models arbitrarily well in asymptotically large markets. Our conditions require that the distribution of firm states in SE obeys a certain “light-tail” condition. In a second set of results, we show that the set of OE of a finite model approaches the set of SE of the infinite model in large markets under a similar light-tail condition.     

A live experiment on approval voting

This paper presents a large-scale experiment on the Approval Voting rule that took place during the 2002 French presidential election. We describe the experiment and its main results. The findings are as follows: (i) Such an experiment is feasible, and very well accepted by voters. (ii) The principle of approval voting is easily understood and accepted. (iii) Within the observed political context, compared to the official first-round vote, approval voting modifies the overall ranking of candidates. (iv) The candidates Le Pen and Chirac, more than the others, were able to convert approval votes into official first-round votes. JEL Classification C93, D70, D72     

DOES GNP EXAGGERATE GROWTH IN “ACTUAL” OUTPUT? THE CASE OF THE UNITED STATES

Measures of national product can be misleading because there is nonmarket production. There are also distortions due to transactional activities, which are expenditures to support transactions, not actual output consumed. For 1950–89, this study recalculates output for the United States, adjusting for transactional activities and nonmarket production. Due to relatively rapid growth in transactional activities, GNP overstates output growth in the 1950s; because there was slow expansion of transactional activities in the early 1970s, GNP understates actual output. Since 1974, increases in transactional activities and shifts to market production lead GNP to exaggerate improvement of "actual" output per capita.     

What does it mean to find the face of the franchise? Physical attractiveness and the evaluation of athletic performance

We show that attractiveness, as measured by facial symmetry, leads to greater rewards in professional sports. National Football League quarterbacks who are more attractive are paid greater salaries and this premium persists after controlling for player performance.     

A new proof of the maximum principle

Summary. We offer a new proof of the maximum principle, by using the envelope theorem that is frequently used in the standard microeconomic theory. Received: April 11, 2002; revised version: June 26, 2002 Correspondence to: K. Shimomura     

Partisanship and the effectiveness of oversight

We examine the welfare effects of partisanship in a model of checks and balances. An executive makes a policy proposal and an overseer then decides whether or not to veto the executive's proposal. Both the executive and the overseer have private information as to the correct policy to pursue, and both are motivated by the desire to appear competent. A partisan overseer is one who, in addition to seeking to promote her own reputation, cares how her decision will impact the executive's reputation. Our main result is that partisanship can improve the efficacy of an oversight regime, as the distortions caused by a partisan overseer's desire to affect the executive's reputation can offset the distortions caused by her desire to enhance her own. Our results provide a new rationale for divided government, as partisan considerations are often necessary to prevent the overseer from rubber stamping all executive proposals.     

How much does household collateral constrain regional risk sharing?

We construct a new data set of consumption and income data for the largest US metropolitan areas, and we show that the extent of risk-sharing between regions varies substantially over time. In times when US housing collateral is scarce nationally, regional consumption is about twice as sensitive to income shocks. We also document higher sensitivity in regions with lower housing collateral. Household-level borrowing frictions can explain this new stylized fact. When the value of housing relative to human wealth falls, loan collateral shrinks, borrowing (risk-sharing) declines, and the sensitivity of consumption to income increases. Our model aggregates heterogeneous, borrowing-constrained households into regions characterized by a common housing market. The resulting regional consumption patterns quantitatively match those in the data.     

On the unique features of post-disaster humanitarian logistics

Logistic activity can be thought of as a socio-technical process whereby a social network of individuals orchestrates a series of technical activities using supporting systems such as transportation and communications. To understand the functioning of the entire system requires proper consideration of all its components. We identify seven key components: the objectives being pursued, the origin of the commodity flows to be transported, knowledge of demand, the decision-making structure, periodicity and volume of logistic activities, and the state of the social networks and supporting systems. Based on our analysis of the differences between commercial and humanitarian logistics, we pinpoint research gaps that need to be filled to enhance both the efficiency of humanitarian logistics and the realism of the mathematical models designed to support it.We argue that humanitarian logistics is too broad a field to fit neatly into a single definition of operational conditions. At one end of the spectrum we find humanitarian logistic efforts of the kind conducted in long-term disaster recovery and humanitarian assistance, where operational efficiency – akin to commercial logistics – is a prime consideration. At the other, post-disaster humanitarian logistic operations involved in disaster response and short-term recovery activities represent a vastly different operational environment, often in chaotic settings where urgent needs, life-or-death decisions and scarce resources are the norm. The huge contrast between these operational environments requires that they be treated separately.     

Too close for comfort? Distinguishing between team intimacy and team cohesion

The authors examine theory and research on team intimacy and team cohesion, and argue that the two have often been confused, merged, and used interchangeably in recent theoretical, empirical, and applied work on team effectiveness. The authors propose distinct definitions to clarify and distinguish between team intimacy and team cohesion, and suggest areas that will aid research and application. Their examination provides a framework for understanding the inconsistent findings in team effectiveness and team building research and thus helps to improve human resource management (HRM) interventions.