MSE-improvement of the least squares estimator by dropping variables

It is well known that dropping variables in regression analysis decreases the variance of the least squares (LS) estimator of the remaining parameters. However, after elimination estimates of these parameters are biased, if the full model is correct. In his recent paper, Boscher (1991) showed that the LS-estimator in the special case of a mean shift model (cf. Cook and Weisberg, 1982) which assumes no “outliers” can be considered in the framework of a linear regression model where some variables are deleted. He derived conditions under which this estimator outperforms the LS-estimator of the full model in terms of the mean squared error (MSE)-matrix criterion. We demonstrate that this approach can be extended to the general set-up of dropping variables. Necessary and sufficient conditions for the MSE-matrix superiority of the LS-estimator in the reduced model over that in the full model are derived. We also provide a uniformly most powerful F-statistic for testing the MSE-improvement.     

Profit,productivity, and profit-sharing

This study is an investigation of the effect of profit-sharing on labor productivity. When monitoring labor performance is costly for management, a regular wage/salary contract is insufficient to induce profit-maximizing behavior from the worker. The authors demonstrate that when this profit-maximizing behavior can be induced only through profit-sharing, a linear profit-sharing program will increase productivity and the welfare of both management and labor. The benefit from profit-sharing is increasing up to the point where the utility of additional income is offset by the negative utility of extraordinary effort (working harder or providing higher quality work). The income effect, i.e., the change in negative utility of extraordinary effort given a change in income, can potentially either increase or decrease the point at which the income-effort tradeoff-reaches zero.     

Optimal fiscal zoning when the local government is a discriminating monopolist

Monopoly zoning by local governments has been studied extensively since the original article by White [1975, in: E. Mills and W. Oates, eds., Fiscal zoning and land use controls (Lexington Books, Lexington, MA)]. However, little or no attention has been paid to the possibility of monopolistic discrimination under such a regime. The question is: When will zoning multiple lot sizes be feasible given that buyers with different valuations of land cannot be coerced into purchasing particular lots? The literature on imperfect price discrimination by monopolists is brought to bear on this question. It is shown that the resulting zoning strategy may or may not involve multiple lot sizes. The factors determining the optimal strategy are studied in detail, with particular emphasis on the nature of the market for undeveloped land in the community.     

Alternative sources of technology: An analysis of induced innovations

This paper considers why firms differ in the degree to which they rely on their internal R&D organization for generating new technologies (induced innovations) rather than on existing external technology markets (purchased innovations). An empirical model is suggested to explan inter-firm differences in the percentage of new technology induced through R&D efforts. The analysis suggests that such differences are systematically related to the firm's size, its competative environment, and its degree of diversification.     

Analysis of arrest rates for trends in criminality

During the 1960s, the United States experienced a substantial increase in crime with the rates of reported crime more than doubling. It has been postulated that the increase in the proportion of young adults in the population which also occurred during the Sixties is a primary factor in the increase in crime. In this paper, we attempt to explore this question by partitioning the recent increases in rates between an increasing crime-committing propensity for various demographic groups on one hand, and a changing demographic mix to the other. We do this by analyzing arrest rates by demographic group over time. However, since arrest rates are a complex function of both criminality and police activity, a model is developed which attempts to distinguish between these phenomena. The model is estimated using data on age, race, and sex-specific arrest rates for Pittsburgh residents over the period 1967–1972. The results of the analysis suggest that there has been no significant increase in criminality for men in the Pittsburgh population, while there is some evidence of increased criminality for women. However, this increase may reflect an increased willingness of the police to arrest women. We hesitate to generalize our conclusions too widely from the experience of a single urban center. Additional analysis, using the model developed here, of arrest rates from other cities or regions would do much to illuminate this very significant issue.     

BOOK REVIEWS AND NOTES

Book reviews in this article: G.D.H. COLE AND INDUSTRIAL DEMOCRACY: A REVIEW: The World of Labour Introduction by John Lovell G.D.H. COLE AND INDUSTRIAL DEMOCRACY: A REVIEW: Self-Government in Industry Introduction by J. G. Corina G.D.H. COLE AND INDUSTRIAL DEMOCRACY: A REVIEW: Workshop Organisation Introduction by A. I. Marsh WORKPLACE INDUSTRIAL RELATIONS: Building: Teamwork or Conflict? by L. G. Bayley The Management of Wage Payment Systems by Alan Gillespie Labour Relations on the Docks by M. Jackson ORGANIZATIONAL BEHAVIOUR: Social Psychology of the Work Organisation by A. S. Tannenbaum Organisational Problems in European Manufacture by T. D. Weinshall LABOUR ECONOMICS: Manpower Economics by E. B. Jakubaus and Neil A. Palomba Labour Economics by J. E. King Unemployment and Wage Inflation with Special Reference to Britain and the U.S.A. by J. Taylor UNEMPLOYMENT: Regional Unemployment Differences in Great Britain by P. C. Cheshire Interregional Migration Models and their Application to Great Britain by R. Weeden The Changing Pattern of Employment—Regional Specialisation and Industrial Localisation in Britain by M. Chisholm and J. Oeppen Men Out of Work—A Study of Unemployment in Three English Towns by M. J. Hill, R. M. Harrison, A. V. Sargeant and V. Talbot Do The Poor Want To Work? A Social-Psychological Study of Work Orientation by L. Goodwin Marienthal: The Sociography of an Unemployed Community by M. Jahoda, P. F. Lazarsfeld and H. Zeisel b