Heterogeneity and Share Contracting in Medical Group Practices

This paper offers an empirical analysis of the relationship between income sharing rules and physician heterogeneity in medical group practices.The economies to group formation associated with risk–sharing, mutual monitoring,and internal referral are served by sharing at least a portion of group income equally. Sharing group income equally is problematic, however, when group members differ in their contribution to group income. Member contributions to group income may differ because of differences in ability, effort, or the price of services across specialty fields. The analysis below is addressed to the question of how income sharing rules in physician groups are affected by variation in member contributions. The analysis finds evidence that heterogeneity in member contributions to group income limits the use of equal income sharing rules in multispecialty groups relative to single specialty groups, and large groups relative to small groups. Nevertheless, 65% of all groups in the survey share at least a pn of group income equally, which broadly suggests that the joint surplus enhancement from risk sharing, mutual monitoring, and internal referral are sufficient to overcome the incentive problems of such rules     

Income distribution and inequality measurement: The problem of extreme values

We examine the statistical performance of inequality indices in the presence of extreme values in the data and show that these indices are very sensitive to the properties of the income distribution. Estimation and inference can be dramatically affected, especially when the tail of the income distribution is heavy, even when standard bootstrap methods are employed. However, use of appropriate semiparametric methods for modelling the upper tail can greatly improve the performance of even those inequality indices that are normally considered particularly sensitive to extreme values.     

Proportionally adjusted marginal pricing method to share joint costs

We consider the cost sharing problem with divisible demands of heterogeneous goods. We propose a cost sharing method called Proportionally Adjusted Marginal Pricing (PAMP) method. PAMP is a nonadditive (in the cost function) extension of average cost pricing. We introduce an axiom called Local Independence (LI) and use LI together with Continuity, Proportionality, and Scale Invariance to characterize PAMP. Received: 23 March 2001 / Accepted: 16 November 2001 I thank Yves Sprumont, Hervé Moulin, and Ahmet Alkan for discussions, comments and suggestions. Thanks also go to the associate editor and the referees, whose comments and suggestions greatly improve the paper.     

Econometric analysis of copyrights

This paper explores the impact of copyrights on firm value and on the demand for firm output. Using panel data on franchise value and ticket sales from the National Football League over the 1991–2000 period, we analyze the effect of copyrights (in this case, team logos) using several parametric estimators, the Arellano and Bond [1991. Some tests of specification for panel data: Monte Carlo evidence and an application to employment equations. Review of Economic Studies 58, 277–297] dynamic panel data estimator, and a semi-non-parametric method based on difference-in-differences propensity score matching. We find a negative effect of logo changes on franchise value that is robust across multiple specifications. In addition, logo changes also appear to have a moderate positive, albeit not particularly robust, impact on ticket sales.     

Regulating Availability with Demand Uncertainty

Abstract. I evaluate a new German regulation that requires retail discounters to guarantee the availability of their products in bargain sales. The regulation is meant to prevent loss leaders. Retailers undermine the regulation's rationale by claiming that rationing is due to demand uncertainty. This paper shows that under demand uncertainty the regulation has ambiguous welfare effects. Effectively, it raises production, which, under imperfect competition, tends to be beneficial. However, the regulation overshoots and decreases welfare if it requires availability for a state of high demand that is relatively unlikely. In this case more sophisticated regulation is required.     

Private labels, price rivalry, and public policy

The article examines (i) why low-quality private labels are introduced in some product categories and not in others, (ii) how the existence of a low-quality private label affects the pricing of a competing national brand, and (iii) how consumers’ surplus and welfare are affected by private labels. We find that the potential for private label introduction may—in return for national brand exclusivity in that particular retail store (exclusive dealing)—lead to price concessions from the producer of the national brand. If the national brand producer decides not to offer an exclusivity contract, a private label is introduced. In this case, private label introduction may lead to higher retail prices on national brands, which can be detrimental to consumer welfare as well as total welfare. We argue that our results have important implications for the interpretation of empirical results and the public policy towards national brands     

Buyer power and supplier incentives

This paper analyzes the origins and welfare consequences of buyer power. We show that if suppliers are capacity constrained or have strictly convex costs, there are two different channels through which large buyers can obtain more favorable terms from their suppliers. In particular, we show how the presence of large buyers can then erode the value of suppliers’ outside option. Somewhat surprisingly, we show how this can induce suppliers to undertake strategies that lead to higher output and potentially higher welfare.     

Unilateral production restrictions in a dynamic duopoly

This paper examines a dynamic game of exploitation of a productive asset by a duopoly. A closed-loop Nash equilibrium of the game is constructed and used to analyze the effects of a unilateral production restriction. Surprisingly, such unilateral action may result in a decrease of the long-run asset's stock. We also exhibit production restrictions that can result simultaneously in an increase of the asset's stock and the long-run profits of the firm that is being imposed the production restriction. Moreover, a unilateral decrease of the production of one firm can induce its rival to also decrease its production.     

The impact of product diversification strategy on the corporate performance of large Spanish firms

We analyze the impact of product diversification on performance. This topic has been discussed in the literature, and there is no consensus so far as to the significance or the direction of the impact. Performance is measured using Tobin's q for a sample of 103 large, non-financial Spanish firms (1992–1995). Diversification is measured by means of a categorical variable, as suggested by Varadarajan. The principal results indicate that the firms with intermediate levels of product diversification have the highest performance, while the firms with low and high levels of diversification show significantly lower performance, which performance is not significantly different between them.