Publication Selection Bias in Minimum‐Wage Research? A Meta‐Regression Analysis

Card and Krueger's meta-analysis of the employment effects of minimum wages challenged existing theory. Unfortunately, their meta-analysis confused publication selection with the absence of a genuine empirical effect. We apply recently developed meta-analysis methods to 64 US minimum-wage studies and corroborate that Card and Krueger's findings were nevertheless correct. The minimum-wage effects literature is contaminated by publication selection bias, which we estimate to be slightly larger than the average reported minimum-wage effect. Once this publication selection is corrected, little or no evidence of a negative association between minimum wages and employment remains.     

Model uncertainty and liquidity

Extreme market outcomes are often followed by a lack of liquidity and a lack of trade. This market collapse seems particularly acute for markets where traders rely heavily on a specific empirical model such as in derivative markets like the market for mortgage backed securities or credit derivatives. Moreover, the observed behavior of traders and institutions that places a large emphasis on “worst-case scenarios” through the use of “stress testing” and “Value-at-Risk” seems different than Savage expected utility would suggest. In this paper, we capture model-uncertainty using an Epstein and Wang [Epstein, L.G., Wang, T., 1994. Intertemporal asset pricing under Knightian uncertainty. Econometrica 62, 283–322] uncertainty-averse utility function with an ambiguous underlying asset-returns distribution. To explore the connection of uncertainty with liquidity, we specify a simple market where a monopolist financial intermediary makes a market for a propriety derivative security. The market-maker chooses bid and ask prices for the derivative, then, conditional on trade in this market, chooses an optimal portfolio and consumption. We explore how uncertainty can increase the bid–ask spread and, hence, reduces liquidity. Our infinite-horizon example produces short, dramatic decreases in liquidity even though the underlying environment is stationary. We show how these liquidity crises are closely linked to the uncertainty aversion effect on the optimal portfolio. Effectively, the uncertainty aversion can, at times, limit the ability of the market-maker to hedge a position and thus reduces the desirability of trade, and hence, liquidity.     

Do We Have a Redundant Set of Cost–Efficiency Targets in the NHS?

There has been a long history of hospital trust cost–efficiency targets being used in the National Health Service (NHS), but there is little evidence about whether they are effective in reducing hospital unit costs and reducing the dispersion of unit costs between trusts. In 1997, the new Labour government announced that it would replace the purchaser efficiency index with a new approach to securing cost–efficiency gains from trusts. Since 1999/2000 trust efficiency targets have been based on reference costs. This article presents evidence to suggest that efficiency targets have not been effective and that the new reference cost based system of targets is irrelevant. The efficiency gains that trusts seek to achieve are those that emerge from the purchaser funding formula and the contracting process.     

Developing global products and marketing strategies: A rejoinder

In this issue of JAMS, Dr. Lyn Amine presents a “comment and an extension” to our previously published article. Such efforts are often constructive, and in this spirit, we present a discussion responding to Dr. Amine’s comments. Our response, combined with Dr. Amine’s comments, hopefully will provide constructive research avenues in international product and marketing strategy development. He has published extensively in the areas of international marketing and retailing. His research and publication areas include international marketing, high tech marketing, and advertising management. His research and publication interests include sales management, international marketing, and retail management.     

Schedule evaluation in unstable manufacturing environments

This paper provides a new approach to validate the feasibility of schedules of multiple-step mixed-model unstable manufacturing environments with different changeover times. Traditionally, continuous lines in a manufacturing process run the same sequence in order to minimize WIP inventory and lead time. Nevertheless, multiple reasons such as different product mixes or setup times can lead managers to run different sequences in continuous lines. Unfortunately, lack of reliability of supply and demand in these environments makes it difficult to manage product inventories and often leads to starvation due to the discoordination between the schedules of both lines. This approach is based on a new type of visual representation of schedules and an estimate the probability of starvation. It assumes stochastic supply and demand and a predefined schedule sequence based on batches of different sizes.     

Dynamics and Long-run Structure in U.S. Meat Demand

Empirical analysis, based on a general dynamic Almost Ideal Demand System, shows the commonly used autoregressive and partial adjustment processes are restrictive to meat demand data. This study derives a linear specification in levels form to investigate dynamics in a general framework. Merging a long-run steady state structure with short-run dynamics results in consistent and robust long-run demand elasticities Une analyse empirique, basée sur un systéme dynamique général de demande quasi optimale, montre que les mécanismes courants d'ajustement autorégressif et d'ajustement partiel ont un effect restrictif sur l'évaluation des données de la demande de viande. Les auteurs proposent une spécifcation linéaire par niveaux pour examiner la dynamique du cadre général. La combinaison d'une structure stable de longue durée avec une dynamique de courte période a produit des élasticités cohérentes et solides de la demande à long terme