The administrative costs of non-profit health insurers

Interest in the efficiency or inefficiency of non-profit firms has spawned research on the administrative costs of Blue Cross and Blue Shield plans. Relying on plausible implications of the property rights theory of the firm, both Blair, Ginsburg, and Vogel (1975) and Vogel (1977) noted some evidence of inefficiency in these firms. Our analysis, however, utilizing their models and more recent data, reveals little convincing evidence for the view that Blue Shield plans are inefficient.     

Federal statistics in a complex environment: the case of the 1980 census

A discussion of the 1980 U.S. census is presented. The authors suggest that the taking of a national census is not just a statistical exercise, but an exercise involving ethics, epistemology, law, and politics. They contend that conducting a national census can be defined as an ill-structured problem in which the various complexities imposed by multidisciplinarity cannot be separated. "The 1980 census is discussed as an ill-structured problem, and a method for treating such problems is presented, within which statistical information is only one component."     

Ethnicity,immigration process and short-term occupational mobility

The relationship between the ethnic characteristics of immigrants to the United States and their occupational mobility in the short term is explored. The data concern the period 1965-1970 and are taken from the 1970 census. The results indicate that race and sociocultural distance have important effects on occupational mobility. The study also shows that if educational status is controlled, the performance of Asian immigrants is more similar to that of blacks or Hispanics than it is to that of whites. (summary in FRE, SPA)     

Sensitivity of the Optimum to Perturbations of the Profit or Weight of an Item in the Binary Knapsack Problem

In the binary single constraint Knapsack Problem, denoted KP, we are given a knapsack of fixed capacity c and a set of n items. Each item j, j = 1,...,n, has an associated size or weight w_j and a profit p_j. The goal is to determine whether or not item j, j = 1,...,n, should be included in the knapsack. The objective is to maximize the total profit without exceeding the capacity c of the knapsack. In this paper, we study the sensitivity of the optimum of the KP to perturbations of either the profit or the weight of an item. We give approximate and exact interval limits for both cases (profit and weight) and propose several polynomial time algorithms able to reach these interval limits. The performance of the proposed algorithms are evaluated on a large number of problem instances.     

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