On the Role of Weight Restrictions in Data Envelopment Analysis

This paper examines the role that weight restrictions play in Data Envelopment Analysis (DEA). It is argued that the decision to include a factor (input or output) in a DEA model represents an implicit judgement that the factor has a non-trivial weight. It therefore seems perverse to allow DEA to assign a trivial weight to that factor in assessing the efficiency of a unit. There is therefore a strong case for imposing restrictions on factor weights. However, many existing methods of weight restriction are in practice unwieldy. This paper proposes an alternative approach we term contingent weight restriction which is both practical and intellectually consistent with the DEA philosophy. The paper explores the implications of alternative methods of weight restriction using simulated data from a well known production process.     

The right cure for health care

An aging population with nearly unlimited access to high-priced doctors and technology is pushing medical costs skyward. Managed care is the best way to bring them down.     

Ownership structure and golden parachutes: Evidence of credible commitment or incentive alignment?

Using a sample of S & P 500 firms, we find that golden parachutes are associated with concentrated external ownership, less concentrated internal ownership, and non-Delaware incorporation. We find little support that concentrated external owners use golden parachutes as credible commitment devices. The general multivariate results support the incentive alignment hypothesis, and reaffirm the view that golden parachutes are a mechanism used to align managerial and shareholder interests when there is a separation between ownership and control. (JEL G32)     

Onsite concurrent review: impacts on utilization, medical complications and expense

An evaluation of onsite concurrent review over and above the effects of Aetna's precertification program demonstrated reduced utilization and expenses, especially for ancillary services, and no adverse effects on rates of medical complications.     

Is Meta-Analysis a Noah's Ark for Non-Market Valuation?

This paper describes meta-analytical methods as they have been appliedto non-market valuation research. These studies have been used to reviewand synthesize literature and, more recently, in benefit transfer. Thissecond use imposes a higher standard on the consistency in economicconcepts being summarized and in the resources included in ameta-analysis. To meet this need, the paper proposes and illustrates astructural framework using a generalized method of moments estimator toestimate the parameters of a preference function with the benefitsestimates usually encountered in meta-analytic summaries.     

Hedonic models and air pollution: Twenty-five years and counting

This paper reports a meta analysis of how effectively hedonic property models have detected the influence of air pollution on housing prices. Probit estimates are reported describing how data, model specification, and local property market conditions in cities represented in thirty-seven studies influence the ability of hedonic models to uncover negative, statistically significant relationships between housing prices and air pollution measures.Partial support for this research was provided by the Russell Sage Foundation. Thanks are due David Cordray, Heidi Hartman, and Larry Hedges of the Foundation's Meta-Analysis Panel for constructive comments, to Ray Palmquist for suggestions and assistance in assembling the results from his studies, to Rick Freeman and Tom Tietenberg and two anonymous referees for comments on the research, and to Barbara Scott for constructive editing of earlier drafts of this paper.     

Strategic freedom, constraint, and symmetry in one-period markets with cash and credit payment

Summary. In order to explain in a systematic way why certain combinations of market, financial, and legal structures may be intrinsic to certain capabilities to exchange real goods, we introduce criteria for abstracting the qualitative functions of markets. The criteria involve the number of strategic freedoms the combined institutions, considered as formalized strategic games, present to traders, the constraints they impose, and the symmetry with which those constraints are applied to the traders. We pay particular attention to what is required to make these strategic market games well-defined, and to make various solutions computable by the agents within the bounds on information and control they are assumed to have. As an application of these criteria, we present a complete taxonomy of the minimal one-period exchange economies with symmetric information and inside money. A natural hierarchy of market forms is observed to emerge, in which institutionally simpler markets are often found to be more suitable to fewer and less-diversified traders, while the institutionally richer markets only become functional as the size and diversity of their users gets large.Received: 5 June 2003, Revised: 18 November 2003, JEL Classification Numbers: C7, G10, G20, L10, D40, D50. Correspondence to: Eric SmithEric Smith, Martin Shubik: We are grateful to Lloyd Shapley, Duncan Foley, and Doyne Farmer for discussions in the course of this work.