A METHOD FOR SOLVING LINEAR PROGRAMS WITH VARIABLE RESOURCES

This paper is concerned with the solution of linear and linear goal programming problems in which the values of the right-hand side parameters are not fixed constants. Specifically, we are concerned with linear optimization problems in which the right-hand sides of the constraining equations are free to vary subject to a set of linear constraining equations. By formulating a relaxed linear program wherein the right-hand sides are treated as variables, we show how it is possible to solve one larger linear program that yields as a solution not only the optimal values for the decision variables, but also the optimal values for the right-hand sides.     

Is the Precautionary Principle Really Incoherent?

The Precautionary Principle has been an increasingly important principle in international treaties since the 1980s. Through varying formulations, it states that when an activity can lead to a catastrophe for human health or the environment, measures should be taken to prevent it even if the cause‐and‐effect relationship is not fully established scientifically. The Precautionary Principle has been critically discussed from many sides. This article concentrates on a theoretical argument by Peterson (2006) according to which the Precautionary Principle is incoherent with other desiderata of rational decision making, and thus cannot be used as a decision rule that selects an action among several ones. I claim here that Peterson's argument fails to establish the incoherence of the Precautionary Principle, by attacking three of its premises. I argue (i) that Peterson's treatment of uncertainties lacks generality, (ii) that his Archimedian condition is problematic for incommensurability reasons, and (iii) that his explication of the Precautionary Principle is not adequate. This leads me to conjecture that the Precautionary Principle can be envisaged as a coherent decision rule, again.     

Homogamy by education and migration status in Monterrey,Mexico: changes and continuities over time

This paper reviews changes in homogamy by migration status and educational level in Monterrey, Mexico, through the analysis of marriage patterns for two cohorts of men born in 1905–1934 and 1940–1969. Results show a significant increase in educational homogamy, as well as in homogamy by rural origins. The changes suggest that education has played an increasingly important role in the process of mate selection, although certain particularistic characteristics, such as being a rural immigrant, are still important in marriage formation. The paper concludes with a discussion of the implications of these findings for the relationship between homogamy and social stratification.

Welfare judgments and future generations

The author argues that long-range welfare policies - policies designed to provide significant, widespread, continuing benefits to future generations, remote as well as near, at some cost to ourselves - cannot be justified by appeal to the welfare of remote future generations. He questions whether they can be justified at all. The problem is that the failure to adopt such a policy would not make any of our distant descendants worse off that he would otherwise be, since had the policy been adopted, he would not even have existed. These considerations also bring out a conflict between utilitarian and Paretian principles.     

On misunderstanding ‘understanding’

Philosophers of Science have recently put a good deal of energy into locating the precise methodological boundaries between the natural and the social sciences. The methodological affinities of the latter with certain aspects of the humanities have been as yet too little explored. A convenient starting point for this discussion, and one which is adopted in this paper, is a reconsideration of the role and nature of interpretive understanding in the social sciences. However, before a serious examination of this issue can be undertaken, a clearing operation on the encrusted misunderstandings which are part of the legacy of logical positivism is necessary. In this paper I argue that the neo-positivistic account of understanding rests on a misunderstanding of the concept; that a more adequate conception of the issues involved - and one closer to the traditional Verstehen problematic of Dilthey et al. - can be gleaned from the work of Peter Winch; and that this development is furthered in a number of important respects by recent work done in hermeneutic philosophy - especially that of H.-G. Gadamer. The discussion of Gadamer suggests that the problem of locating the boundaries with the humanities might be as serious a problem for the theory of the social sciences as has been that concerning the natural sciences. The paper concludes with several suggestions as to the implications of the analysis of understanding for the thesis of the methodological unity of the sciences.     

Making Sense of the Census: Why Sampling Might Not Be so Simple

Population and Environment -     

Moving and union dissolution

This paper examines the effect of migration and residential mobility on union dissolution among married and cohabiting couples. Moving is a stressful life event, and a large, multidisciplinary literature has shown that family migration often benefits one partner (usually the man) more than the other Even so, no study to date has examined the possible impact of within-nation geographical mobility on union dissolution. We base our longitudinal analysis on retrospective event-history data from Austria. Our results show that couples who move frequently have a significantly higher risk of union dissolution, and we suggest a variety of mechanisms that may explain this.     

Relationships Between Population Density and the Perceived Quality of Neighbourhood

Two overseas survey-based scales measuring perceived quality of neighbourhood were adapted and replicated in a New Zealand context. An Italian study (Bonaiuto, Fornara, and Bonnes. (2003). Landscape and Urban Planning, 65, 41–52) measuring Perceived Residential Environmental Quality (PREQ) and an American study (Carp and Carp. (1982). Journal of Environmental Psychology, 2, 295–312) using the Perceived Environmental Quality Indices (PEQI) were applied to a sample of Auckland residents, separated into low, medium, and high population density areas. The surveys measured attitudes towards subjects such as noise, neighbours, accessibility, green areas, welfare services, recreational services, safety, maintenance, environmental health, transport services, and characteristics of an ideal neighbourhood, and were completed by 369 respondents. Primary analyses examined differences in perception across the three density groups. The factor structures of both scales were replicated with the Auckland sample, and differences across densities were found for subscales of the PREQ. The results are discussed in relation to the cross-cultural similarities of perceived environmental quality, and the concept that environmental satisfaction is based on balancing aspects of the residential environment is proposed. This research was conducted for the Foundation for Research, Science, and Technology under contract OPSX401.     

ON PREDICTING COMPUTATIONAL TIME OF A BRANCH AND BOUND ALGORITHM FOR THE ASSIGNMENT OF FACILITIES

Experience with branch and bound algorithms indicates that computational time is a function of not only the size of the problem, but also the nature of the input data. This paper formulates statistically-based variables which describe certain characteristics of the input data and experimentally evaluates their ability to predict computational time for one branch and bound algorithm, the relative location of facilities or “plant layout” problem. Results suggest that the described experimental procedure may be useful for an a priori assessment of the computational difficulty of specific branch and bound problems.     

Global liberalization on homosexuality: Explaining the African gap

We are trapped in two divergent worlds when it comes to global views on homosexuality. There is the liberal world epitomized by Spain and other nations, where homosexuality is increasingly accepted; gays and lesbians are claiming their human rights; and laws are changing to codify that transformation. The second is the extremely anti-gay world symbolized by Africa, the Middle East and parts of Asia, where attitudes are favorable to criminalization. This research explains the “African Gap” in attitudes toward homosexuality in a comparative analysis of six African nations and Argentina and Canada, South and North America's most liberal nations on gay rights. Using Pew's 2015 Spring Global Attitudes Survey data, we find that the major variables have essentially similar effects on opinion in any context. Africa's distinction is explained by its comparatively higher levels of factors such as religion, morality dogma, and low socioeconomic status that generally retard support for homosexuality, at the same time of lower levels of factors such as education, urbanization, and personal liberty that increase gay support. Africa's extreme anti-gay outlook is mutable. Two social forces will facilitate this softening: expansion of liberalizing agents such as education and urbanization, and repositioning away from “traditionalism” toward modernism emphasizing individualism, civil rights, and personal liberties.