EQUILIBRIUM INCENTIVE CONTRACTS AND EFFICIENCY WAGES

We analyze the optimal (efficiency) wage contract when output is contractible but firms neither observe the workers' effort nor their match‐specific productivity. Firms offer wage contracts that optimally trade off effort and wage costs. As a result, employed workers enjoy rents, which in turn creates unemployment. Nonetheless, the incentive power of the equilibrium wage contract is constrained efficient in the absence of taxes and unemployment benefits. We also show that more high‐powered incentive contracts tend to be associated with higher equilibrium unemployment rates. (JEL: E24, J30, J41)     

Ownership Structure,Corporate Value and Firm Investment: A Simultaneous Equations Analysis of Spanish Companies

This paper is concerned with the set of mutualrelationships between firm valuation andinvestment, and with the possible endogeneityof ownership structure. In order to deal withthem properly, we aim to test the mutual impactof investment, corporate value and ownership bybroadening the usual framework with asimultaneous equations approach. Using a sampleof 140 Spanish listed companies for the1991–1997 period, we have found that,consistent with previous research, thealignment and entrenchment hypotheses seem tobe confirmed by the estimation of aone-equation model. However, when analyzed bymeans of a system of simultaneous equations inwhich a set of mutual relationships isintroduced, quite different results wereobtained. Although valuation and investment offirms are determined by managerial ownership,we have found that ownership structure may alsobe influenced both by investment and value.Consequently, it is not completely right toinfer that ownership structure determines firmvalue unidirectionally; however the benchmarkshould be broadened so as to take an explicitaccount of the mutual links between firm value,investment and ownership.     

Non-homogeneous Markov models in the analysis of survival after breast cancer

A cohort of 300 women with breast cancer who were submitted for surgery is analysed by using a non-homogeneous Markov process. Three states are onsidered: no relapse, relapse and death. As relapse times change over time, we have extended previous approaches for a time homogeneous model to a non omogeneous multistate process. The trends of the hazard rate functions of transitions between states increase and then decrease, showing that a changepoint can be considered. Piecewise Weibull distributions are introduced as transition intensity functions. Covariates corresponding to treatments are incorporated in the model multiplicatively via these functions. The likelihood function is built for a general model with k changepoints and applied to the data set, the parameters are estimated and life-table and transition probabilities for treatments in different periods of time are given. The survival probability functions for different treatments are plotted and compared with the corresponding function for the homogeneous model. The survival functions for the various cohorts submitted for treatment are fitted to the mpirical survival functions.     

Generalized minimum distance estimators of a linear model with correlated errors

R^p of a linear regression model of the type Y = Xθ + ɛ, where X is the design matrix, Y the vector of the response variable and ɛ the random error vector that follows an AR(1) correlation structure. These estimators are asymptotically analyzed, by proving their strong consistency, asymptotic normality and asymptotic efficiency. In a simulation study, a better behaviour of the Mean Squared Error of the proposed estimator with respect to that of the generalized least squares estimators is observed. Received: November 16, 1998; revised version: May 10, 2000     

Identification of factors influencing dispersion in split-plot experiments

As split-plot designs are commonly used in robust design it is important to identify factors in these designs that influence the dispersion of the response variable. In this article, the Bergman-Hynén method, developed for identification of dispersion effects in unreplicated experiments, is modified to be used in the context of split-plot experiments. The modification of the Bergman-Hynén method enables identification of factors that influence specific variance components in unreplicated two-level fractional factorial splitplot experiments. An industrial example is used to illustrate the proposed method.     

The governance of open source initiatives: what does it mean to be community managed?

The concept of ‘open source’ software initially referred to software projects managed by grassroots communities in public forums. Since 1998, the concept has been adapted and diffused to new settings that extend beyond software. While the open source community has maintained control over which software licenses can be considered ‘open source’, little attention has been paid to the elements that constitute community management. More private parties now contribute to OSS communities and more hybrid governance models have emerged. Before we can understand how hybrid models differ from a community managed model, a more precise definition is needed. This essay takes a step in this direction by identifying five core principles critical to community-managed governance.

Nonparametric estimation of a regression function from backward recurrence times in a cross-sectional sampling

This study considers the nonparametric estimation of a regression function when the response variable is the waiting time between two consecutive events of a stationary renewal process, and where this variable is not completely observed. In these circumstances, our data are the recurrence times from the occurrence of the last event up to a pre-established time, along with the corresponding values of a certain set of covariates. Estimation of the error density function and some of its characteristics are also considered. For the proposed estimators, we first analyze their asymptotic behavior and, thereafter, carry out a simulation study to highlight their behavior in finite samples. Finally, we apply this methodology to an illustrative example with biomedical data.     

Institutions and Service Employment: A Panel Study for OECD Countries

Abstract. We live in a service economy, but the extent of development of service employment differs across developed countries. This paper assesses the role of structural factors and institutions in explaining the common patterns and main differences in the recent expansion of service employment in OECD countries. It finds that GDP per capita, the size of the government sector and the extent of urbanization are positively associated with the service employment share. However, the evidence suggests that laws and institutions such as product market regulations, unions and more coordinated wage‐setting systems are hampering the expansion of service employment.     

The Dynamics of Social Indicator Research for California’s Central Valley in Transition

How can social indicator research improve understanding of community health as well as inform stakeholders about the assets disadvantaged communities have for coping with disparities? This paper describes the development and evolution of the Partnership for Assessment of Communities (PAC) and its best practices for social indicator research. The PAC will be of interest to researchers across multiple disciplines for a number of reasons. First, PAC is a working model of best practices for multidisciplinary scholarly inquiry. Second, it has developed an integrated model of quantitative and qualitative methodology to define and measure community health as compared to traditional quality-of-life indicators. Third, it serves as an example of “action research,” in that the findings have the potential to make an impact on community stakeholders and policy outcomes in the greater Central San Joaquin Valley of California, a region characterized by deep social and economic disparities.