Statistical Methods and Graphical Displays for Analyzing How the Association Between Two Qualitative Variables Differs Among Countries, Among Groups, Or Over Time: A Modified Regression-Type Approach

Many interesting sociological questions pertain to how the association between two variables depends on a third variable. In sociological applications, the third variable often pertains to countries, to subgroups of a population, or to time periods. We propose a regression-type approach that specifies that the log-odds- ratios that describe the two-way association of interest are a linear function of latent scores for the third variable. Additive and multiplicative models currently in use by researchers are special cases of the regression-type model. To illustrate the utility of the regression-type approach, we apply this approach to analyze (1) data on occupational mobility in the United States, Britain, and Japan (comparing mobility in these countries) and (2) data on the association between religion and voting behavior in U.S. presidential elections from 1968 to 1992 (comparing this association in the different elections). We also introduce here graphical displays that can be used to obtain worthwhile information about goodness-of-fit and to aid in substantive interpretation.     

Quality. A tightrope for the '90s

How accurately can you measure quality of care in health care? Recently, HMOs and other types of managed care organizations have been in the process of defining quality in quantitative terms. Physicians who utilize fewer resources and who care for more patients per-unit-of-time are valued as providing better care than colleagues who may work at a slower (more expensive?) pace. The pressure to evaluate or treat greater numbers of patients in shorter periods of time can produce adverse consequences. And numbers do not necessarily take into account the quality of the care delivered. There is clearly a middle road. Physicians must take care of a sufficient number of patients with a given problem to gain and maintain expertise and mastery. But they must also guard against the insidious pressure for the procedure to become the end in itself.     

Marriage selection and age patterns of mortality: a mathematical investigation

"In this paper, we use simulation models to demonstrate the complexity of the relationship between the marriage selection process and the resulting RMRs [relative mortality ratios]. In particular, we show that marriage selection alone can produce a relative mortality ratio which remains large and relatively constant at ages far beyond the marriage span....Our general objective...is to determine the range of age patterns of relative mortality which could, in theory, result from marriage selection on the basis of health characteristics. We also evaluate the effects of variations in the marriage selection mechanisms on the resulting mortality patterns....We develop and apply several simple mathematical models of the marriage selection process. In order to distinguish the potential consequences of marriage selection from marriage protection, we consider hypothetical populations in which causal effects are absent....We begin by considering an extremely simple marriage selection process and subsequently explore a more realistic selection model based on recent death and marriage rates for Japan."     

Explaining the Flight of Cupid’s Arrow: A Spatial Random Utility Model of Partner Choice

Spatial homogamy may be defined as follows: anyone may be attracted to anyone else, but near candidates are more attractive than distant candidates. In this article, we propose a model of partner choice, where homogamy is defined in terms of spatial, demographic, socioeconomic and cultural similarity. A spatial choice model using random utility theory is formulated, taking into account a relaxation of the independence from the irrelevant alternatives property, as spatial alternatives are not independent of one another. We model partner choice given the characteristics of the chosen partner and a choice set of alternatives, using unique micro data on all new cohabiters in the Netherlands, linked to other relevant data sets. The model takes the spatial locations of potential candidates within a choice set into account, including an indicator for the spatial similarity between alternatives. We find that spatial homogamy is a vital component of partner matching, aside from and adding to the spatial effects in demographic, socioeconomic and cultural homogamy. Given a choice set of partners, the highest likelihood of a match occurs with a person who is born and lives near by, who is close in age, is in the same life stage and has the same marital status, who has the same educational and income level and the same labour market status, who speaks the same dialect and lives in a culturally similar residential area. The distance effect is most pronounced for those individuals with lower levels of education and those living in rural areas.     

Mathematical programming: Turing completeness and applications to software analysis

Mathematical programming is Turing complete, and can be used as a general-purpose declarative language. We present a new constructive proof of this fact, and showcase its usefulness by discussing an application to finding the hardest input of any given program running on a Minsky Register Machine. We also discuss an application of mathematical programming to software verification obtained by relaxing one of the properties of Turing complete languages.     

FDI’s Impact on Transitional Countries, Serbia as a Rational Choice: The FIAT-ZASTAVA Case

The privatization process and foreign direct investments (FDI) are among the most important economic issues in transitional countries. FDI has enormous influence on transitional countries that need serious structural changes. In this paper we will study FIAT’s decision to invest in the Serbian automotive industry. We will try to rationalize FIAT’s decision because Serbian car manufacturer ZASTAVA was not the only alternative for FIAT to invest in the Balkans. In order to justify FIAT’s decision we will apply the Mullins model of horizontal and vertical FDI, examine the importance of the cooperating history between two car manufacturers and compare macroeconomic conditions and Global Competitiveness of Serbia and Romania, which was the main alternative for FIAT. Finally, we will also try to explain why FIAT decided to announce the investment at the end of political campaign in Serbia when pools gave anti-European parties higher chances for victory, instead of waiting to see the outcome of the elections.