The struggle over migration policy

We analyze the endogenous determination of migration quota, viewing it as an outcome of a two-stage political struggle between two interest groups: those in favor and those against the proposed migration quota. First, we compare the proposed policies of the two interest groups under random behavior of the government, with and without lobbying. We examine the effect of the status quo and government intervention in the proposal of the quota on its nature, assuming that, with and without government intervention, the uncertain approval of the proposal is the outcome of a lobbying contest between the two interest groups.

Lower bounds on the adaptivity gaps in variants of the stochastic knapsack problem

We consider stochastic variants of the NP-hard 0/1 knapsack problem in which item values are deterministic and item sizes are independent random variables with known, arbitrary distributions. Items are placed in the knapsack sequentially, and the act of placing an item in the knapsack instantiates its size. The goal is to compute a policy for insertion of the items, that maximizes the expected value of the set of items placed in the knapsack. These variants that we study differ only in the formula for computing the value of the final solution obtained by the policy. We consider both nonadaptive policies (that designate a priori a fixed subset or permutation of items to insert) and adaptive policies (that can make dynamic decisions based on the instantiated sizes of the items placed in the knapsack thus far). Our work characterizes the benefit of adaptivity. For this purpose we use a measure called the adaptivity gap: the supremum over instances of the ratio between the expected value obtained by an optimal adaptive policy and the expected value obtained by an optimal non-adaptive policy. We show that while for the variants considered in the literature this quantity is bounded by a constant there are other variants where it is unbounded.     

Min-Sum Bin Packing

We study min-sum bin packing (MSBP). This is a bin packing problem, where the cost of an item is the index of the bin into which it is packed. The problem is equivalent to a batch scheduling problem we define, where the total completion time is to be minimized. The problem is NP-hard in the strong sense. We show that it is not harder than this by designing a polynomial time approximation scheme for it. We also show that several natural algorithms which are based on well-known bin packing heuristics (such as First Fit Decreasing) fail to achieve an asymptotic finite approximation ratio, whereas Next Fit Increasing has an absolute approximation ratio of at most 2, and an asymptotic approximation ratio of at most 1.6188. We design a new heuristic that applies Next Fit Increasing on the relatively small items and adds the larger items using First Fit Decreasing, and show that its asymptotic approximation ratio is at most 1.5604.     

Erratum to: Beyond the urban stream syndrome: organic matter budget for diagnostics and restoration of an impaired urban river

Urban Ecosystems - This article was unintentionally published twice in this journal, by the same authors.     

The <Emphasis Type="Italic">k</Emphasis>-metric dimension

The anti-Ramsey number AR(G, H) is defined to be the maximum number of colors in an edge coloring of G which doesn’t contain any rainbow subgraphs isomorphic to H. It is clear that there is an \(AR(K_{m,n},kK_2)\)-edge-coloring of \(K_{m,n}\) that doesn’t contain any rainbow \(kK_2\). In this paper, we show the uniqueness of this kind of \(AR(K_{m,n},kK_2)\)-edge-coloring of \(K_{m,n}\).     

Differentiating Contemporary Racial Prejudice from Old-Fashioned Racial Prejudice

The present study addresses the distinction between contemporary and old-fashioned prejudice using survey data from a national sample (n = 600) of self-identified whites living in the United States and interviewed by telephone in 2001. First, we examine associations among indicators of contemporary and old-fashioned prejudice. Consistent with the literature, contemporary and old-fashioned prejudice indicators represent two distinct but correlated common factors. Second, we examine whether belief in genetic race differences uniformly predicts both types of prejudice. As might be expected, belief in genetic race differences predicts old-fashioned prejudice but contrary to recent theorizing, it also predicts contemporary prejudice.     

Exceptional contributions to US science by the foreign-born and foreign-educated

This paper contributes to the debate on high-skilled migration byexamining whether the foreign-born and foreign-educated are disproportionatelyrepresented among individuals making exceptional contributions to science and engineering (S & E) in the U.S. Six indicators of scientific achievement areused: individuals elected to the National Academy of Sciences and/or National Academy of Engineering, authors of citation classics, authors of hot papers, the 250 most-cited authors, authors of highly cited patents, and scientistswho have played a key role in launching biotechnology firms. We do not claim that this list is exhaustive, merely illustrative. Using a variety of sources, we are able to determine the birth andeducational origin of 89.3% of the study group of over 4,500 scientists and engineers. For each indicator of scientific achievement, we test to see if the observed frequency by birth (or educational) origin is significantly differentfrom the frequency one would expect given the composition of the scientific labor force in the U.S. We find that although there is some variation by discipline, individuals making exceptional contributions to S & E in the U.S. aredisproportionately drawn from the foreign born. Only in the instance of hot papers in the life sciences were we unable to reject the null hypothesis that the proportion is the same as that in the underlying population. The most frequent country of origin in the life sciences is Great Britain followed by Germany. In the physical sciences the reverse is true. We also find that individuals making exceptional contributions are, in many instances, disproportionately foreign educated, both at the undergraduate and at the graduate level. We conclude that immigrants have been a source of strength and vitalityfor U.S. science and, on balance, the U.S. appears to have benefited from the educational investments made by other countries. We do not investigate, however, whether U.S. scientists and engineers have borne part of thecost of the inflow of foreign talent by being displaced from jobs and/or earning lower wages. Nor do we investigate the cost to the countries of origin.     

Beliefs about the etiology of homosexuality and about the ramifications of discovering its possible genetic origin

Homosexuality is viewed by many as a social problem. As such, there is a keen interest in elucidating the origins of homosexuality among many scholars, from anthropologists to zoologists, from psychologists to theologians. Research has shown that those who believe sexual orientation is inborn are more likely to have tolerant attitudes toward gay men and lesbians, whereas those who believe it is a choice have less tolerant attitudes. The current qualitative study used in-depth, open-ended telephone interviews with 42 White and 44 Black Americans to gain insight into the public's beliefs about the possible genetic origins of homosexuality. Along with etiological beliefs (and the sources of information used to develop these beliefs), we asked respondents to describe the benefits and dangers of scientists discovering the possible genetic basis for homosexuality. We found that although limited understanding and biased perspectives likely led to simplistic reasoning concerning the origins and genetic basis of homosexuality, many individuals appreciated the complex and interactive etiological perspectives. These interactive perspectives often included recognition of some type of inherent aspect, such as a genetic factor(s), that served as an underlying predisposition that would be manifested after being influenced by other factors such as choice or environmental exposures. We also found that beliefs in a genetic basis for homosexuality could be used to support very diverse opinions including those in accordance with negative eugenic agendas.