Is the American health care delivery system ready for change?

In October 1992, the American College of Physician Executives sponsored a study tour to Berlin, Germany, and Amsterdam, Holland. Meetings were held with government officials, third-party payers, and providers, and on-site visits were made at hospitals, clinics, and academic centers. The purpose was to study the health care delivery system in those countries and to share some insights with the countries' hosts on the U.S. system. In a series of reports that began in the July issue of the journal, 5 of the 10 study tour participants describe their impressions of the tour and of the health care systems in the countries that were visited. In this final report, the implications of the German and Dutch systems for reform of the U.S. health care system are discussed.     

Recent migrations from Morocco to Spain

"This study addressed the problem of the Moroccan immigration into Spain within the context of South-North movements, focusing on analyzing provisional data from the last immigrant regularization in the country completed during the end months of 1991."     

Exploration to Foster Career Development

Responses to the Adult Career Concerns Inventory (ACCI: Super, Thompson, Lindeman, Myers, & Jordaan, 1988) were organized through cluster analysis to identify different ways in which adults use exploratory behavior to cope with career development tasks. Significant differences in life-role salience among the types of adult career explorers identified were also investigated. Findings indicated a variety of ways in which adults use exploratory behavior. However, no significant differences were found in life-role salience among the types of career explorers. The discussion explains how career counselors can interpret their clients' ACCI profiles to select appropriate career interventions.     

Occupational status and mobility among undocumented immigrants by gender

Immigration has long been a national and state concern. The 1989 Legalized Population Survey (LPS-1) collected data on illegal immigrants to the US who subsequently became legalized aliens under the provisions of the 1986 Immigration Reform and Control Act. These data are used in a study assessing whether undocumented male and female immigrants improve their earnings and occupational status over time and the extent of variation in occupational status and mobility by gender and region. The data indicate that both undocumented men and women, on average, improved their earnings and occupational status between their first jobs in the US and their jobs just before applying for legalization under the 1986 Immigration Reform and Control Act. However, the earnings, occupational status, and occupational mobility of men were greater than for women.     

Efficient Estimation of a Distribution Function under Quadrant Dependence

LetX₁,X₂, ..., be real-valued random variables forming a strictly stationary sequence, and satisfying the basic requirement of being either pairwise positively quadrant dependent or pairwise negatively quadrant dependent. LetF^ be the marginal distribution function of theX_ips, which is estimated by the empirical distribution functionF_n and also by a smooth kernel-type estimateF_n, by means of the segmentX₁, ...,X_n. These estimates are compared on the basis of their mean squared errors (MSE). The main results of this paper are the following. Under certain regularity conditions, the optimal bandwidth (in the MSE sense) is determined, and is found to be the same as that in the independent identically distributed case. It is also shown thatn MSE(F_n(t)) andnMSE (F^_n(t)) tend to the same constant, asn→∞ so that one can not discriminate be tween the two estimates on the basis of the MSE. Next, ifi(n) = min {k∈{1, 2, ...}; MSE (F_k(t)) ≤ MSE (F_n(t))}, then it is proved thati(n)/n tends to 1, asn→∞. Thus, once again, one can not choose one estimate over the other in terms of their asymptotic relative efficiency. If, however, the squared bias ofF^_n(t) tends to 0 sufficiently fast, or equivalently, the bandwidthh_n satisfies the requirement thatnh³_n→ 0, asn→∞, it is shown that, for a suitable choice of the kernel, (i(n) ?n)/(nh_n) tends to a positive number, asn→∞ It follows that the deficiency ofF_n(t) with respect toF^_n(t),i(n) ?n, is substantial, and, actually, tends to ∞, asn→∞. In terms of deficiency, the smooth estimateF^_n(t) is preferable to the empirical distribution functionF_n(t)     

Circuit optimization via sequential computer experiments: design of an output buffer

In electrical engineering, circuit designs are now often optimized via circuit simulation computer models. Typically, many response variables characterize the circuit's performance. Each response is a function of many input variables, including factors that can be set in the engineering design and noise factors representing manufacturing conditions. We describe a modelling approach which is appropriate for the simulator's deterministic input–output relationships. Non-linearities and interactions are identified without explicit assumptions about the functional form. These models lead to predictors to guide the reduction of the ranges of the designable factors in a sequence of experiments. Ultimately, the predictors are used to optimize the engineering design. We also show how a visualization of the fitted relationships facilitates an understanding of the engineering trade-offs between responses. The example used to demonstrate these methods, the design of a buffer circuit, has multiple targets for the responses, representing different trade-offs between the key performance measures.     

AN EVOLUTIONARY EXPLANATION FOR ROTTEN KIDS

We explore how natural selection acts upon genes for cooperation, altruism and selfishness in an prisoner's dilemma played by family members. A key parameter determining behavior is that parents and children have different expectations of future offspring. Examining asexual and sexually reproducing populations we show that which strategy of cooperation and defection proves be stable depends on the relative reproduction potential of the players and what proportion of the population is young. "Rotten kids" with altruistic parents can be a stable outcome where reproductive success is the goal, and natural selection may lead individuals to care about their unborn progeny. (JEL D10, H31)