Quality assurance in managed vision benefits

Quality assurance is an important responsibility of those who purchase managed vision care benefits. In conducting a quality assurance program, it is important to respect patient confidentiality and the practitioner's right to exercise professional discretion. An effective program will not only accomplish its main objective of attaining high-quality care, but it can also enhance member satisfaction and improve provider relations.     

Cycle and Trend in Models of the Range of Equilibria

This paper investigates the potential of models of the range of equilibria to yield a pattern of equilibrium rates of unemployment that is consistent with the observed mix of cycle with no trend in the rate of unemployment. To do this the paper considers a model in which wages are determined by a group of unionised insiders bargaining with an employer. In the model the supply of labour is endogenous. Specifications of the utility function are found which are consistent with the mix of cycle and no trend in the rate of unemployment. Of these it is concluded that loss aversion in the evaluation of wage relativities is a crucial ingredient for models of the range of equilibria.     

The rank and model specification of demand systems: an empirical analysis using United States microdata

A rank-three demand system is estimated with United States Consumer Expenditure Survey microdata. A unique price data set is also used, which permits the analysis of effects of systematic errors in price variables. It is found that errors in price variables bias test results for the rank-three hypothesis, in particular towards rejection. Other test results are affected to a lesser extent. Estimating smaller systems of demand equations, even when conditioning on excluded goods, yields significantly different results. Another important conclusion is that model specification is statistically significantly different for households of varying family sizes and housing tenure statuses. JEL Classifications: C31, D12.
Le rang et la spécification du modèle des systèmes de demande: une analyse empirique utilisant des microdonnées américaines. On calibre un système de demande de rang trois à l'aide de microdonnées américaines tirées de la United States Consumer Expenditures Survey. Un ensemble unique de prix est utilisé afin de permettre l'analyse des effets d'erreurs systématiques dans les variables de prix. Il appert que les erreurs dans les variables de prix distorsionnent les résultats du test de l'hypothèse de rang trois en faveur d'un rejet. D'autres résultats de tests sont affectés à un moindre degré. Si l'on calibre de plus petits systèmes d'équations de demande, même en posant des conditions sur des biens exclus, des résultats qui diffèrent de manière significative s'ensuivent. Une autre conclusion importante est que la spécification du modèle est différente de manière statistiquement significative pour les ménages selon la taille de la famille et le statut domiciliaire.     

Using the gravity equation to differentiate among alternative theories of trade

The simple gravity equation explains a great deal about the data on bilateral trade flows and is consistent with several theoretical models of trade. We argue that alternative theories nevertheless predict subtle differences in key parameter values, depending on whether goods are homogeneous or differentiated and whether or not there are barriers to entry. Our empirical work for differentiated goods delivers results consistent with the theoretical predictions of the monopolistic-competition model, or a reciprocal-dumping model with free entry. Homogeneous goods are described by a model with national (Armington) product differentiation or by a reciprocal-dumping model with barriers to entry. JEL Classification: F10, F12
Equation de gravité et différenciation entre diverses théories du commerce international. La simple équation de gravité fournit une bonne part d'explication des flux de commerce bilatéraux et donne des résultats compatibles avec plusieurs modèles de commerce international. Les auteurs suggèrent que les diverses théories prédisent néanmoins des différences subtiles dans les valeurs de paramètres clés, selon que les biens sont homogènes ou différenciés, et qu'il y a barrières ou non à l'entrée. Le travail empirique des auteurs livre des résultats compatibles avec les prévisions théoriques du modèle de concurrence monopolistique ou du modèle de dumping réciproque avec entrée libre. On décrit les flux de biens homogènes à l'aide d'un modèle de différenciation nationale de produit à la Armington ou par un modèle de dumping réciproque avec barrières à l'entrée.     

Office triage and the physician's supply curve

This paper contains a theoretical and empirical model of the physician firm. The utility maximizing physician chooses the number of hours of labor to supply and the mix between patient visits and time per visit. Theory suggests that a serious specification error may occur if one estimates the labor supply curve and patient demand curve without simultaneously estimating the mix between patient visits and time per visit. A Chi-Square specification test reveals that this “triage” model statistically dominates the simple supply/demand model. Estimation results indicate relevant backward-bending labor and negatively sloped service supply functions.     

Organized medicine's new turf: e-services

Stodgy medical societies are partnering with, and creating, online companies. What can they do for your practice?     

Real and financial effects of insider trading with correlated signals

Summary. In this paper we study the real and financial effects of insider trading in a Static, Kyle-type model. In our model the insider is also the manager of the firm. Hence the insider chooses both the amount of the real output to be produced and the amount of the stock of the firm to trade. The aim of the paper is to study the relationship between financial decisions and real decisions. In particular, we examine how insider trading on the stock market affects the real output and price and how the real decision making affects the financial variables, such as the extent of insider trading, stock prices, and the stock pricing rule of the market maker. In the model, the market maker observes two correlated signals: the total order flow and the market price of the real good. We study the informativeness of the stock price and the effects on insider's profits. We also construct a compensation scheme that aligns the interests of the insider and the firm. Finally, we generalize the pricing rule set up by a competitive market maker and analyze the comparative statics of the model. Received: October 3, 1999: revised version: December 1, 1999     

Estimating Recreation Preferences Using Hedonic Travel Cost and Random Utility Models

Over the last decade, several authors have questioned thevalidity of the hedonic travel cost model, arguing instead that the random utility model is a superior method forvaluing recreational site attributes. This paper demonstrates that the two methods emanate from a similar utilitytheoretic framework; yet in practice these methods differ in the assumptions made in their application.Constraining the underlying utility functions to be consistent, both models are applied to the valuation ofrecreational site attributes in the Southeastern United States. The way in which each method estimates preferencesfor site attributes is shown to depend critically on the method and the functional form of theunderlying utility function.