Carrying Firearms for Protection: A Causal Model*

The authors develop a causal model of the determinants of carrying firearms for protection. It is argued that the examination of carrying a gun as a dependent variable is methodologically more advantageous than using gun ownership as the dependent variable. Through use of path analysis, the direct and indirect effects on gun carrying behavior are identified. The results suggest most crime specific variables, e.g. fear of criminal victimization, do not directly influence the tendency to carry a gun, although these factors had minor indirect effects on the dependent variable. The most important direct influences on carrying a gun were age, gender, and the belief that the presence of guns is an effective deterrent to crime.     

The Polls: Regulation--Part I

Part II of this report will appear in the Fall 1984 issue.     

Of designs and disappointments: Some limits to participatory research in a third world context

This paper introduces issues associated with the practice of participatory research (PR) in a Third World context by describing the experience of carrying out a study of urban housing cooperatives in Zimbabwe. A contrast is presented between the PR model, derived from the literature, and the implementation of this model. Five explanations for the discrepancy are proposed, including: differences between the rural and urban context, the questionable suitability of PR for multiple and concurrent case studies, and the need for early intervention. The paper concludes that a methodology is needed for assessing whether a given research context is appropriate for application of a PR model.     

Vector autoregression and causality: a theoretical overview and simulation study

This paper provides a theoretical overview of Wald tests for Granger causality in levels vector autoregressions (VAR's) and Johansen-type error correction models (ECM's). The theory is based on results in Toda and Phillips (1991a) and allows for stochastic and deterministic trends as well as arbitrary degrees of cointegration. We recommend some operational procedures for conducting Granger causality tests that are based on the Gaussian maximum likelihood estimation of ECM's. These procedures are applicable in the important practical case of testing the causal effects of one variable on another group of variables and vice versa. This paper also investigates the sampling properties of these testing procedures through simulation exercises. Three sequential causality tests in ECM's are compared with conventional causality tests in levels and differences VAR's.     

Choosing the best population development goal]

Optimizing goals for controlled population growth and development through mathematical modeling has a practical value and is of important theoretical significance. An integrated model for optimizing multiple interactive targets for population development is proposed. A wide array of user-prioritized (weighted) economic indices or factors may be incorporated into this n-tuple m-dimensional model, by which complex linear and vector space computations are solved and interpreted through conventional mathematics. Although this numerical approach toward problem solving is imperfect, when properly used, the mathematical model presented in this paper is a practical and efficient means for solving multidimensional problems.     

[The change of the population age structure and employment].]

The age structure of the population and its impact on employment in China is studied. The author notes that the demographic transition has occurred rapidly and that changes in the age structure have created employment problems in various regions of the country. Data are from official Chinese sources. The impact of changes in the age structure on employment over the next 30 years is considered.