Analysis of arrest rates for trends in criminality

During the 1960s, the United States experienced a substantial increase in crime with the rates of reported crime more than doubling. It has been postulated that the increase in the proportion of young adults in the population which also occurred during the Sixties is a primary factor in the increase in crime. In this paper, we attempt to explore this question by partitioning the recent increases in rates between an increasing crime-committing propensity for various demographic groups on one hand, and a changing demographic mix to the other. We do this by analyzing arrest rates by demographic group over time. However, since arrest rates are a complex function of both criminality and police activity, a model is developed which attempts to distinguish between these phenomena. The model is estimated using data on age, race, and sex-specific arrest rates for Pittsburgh residents over the period 1967–1972. The results of the analysis suggest that there has been no significant increase in criminality for men in the Pittsburgh population, while there is some evidence of increased criminality for women. However, this increase may reflect an increased willingness of the police to arrest women. We hesitate to generalize our conclusions too widely from the experience of a single urban center. Additional analysis, using the model developed here, of arrest rates from other cities or regions would do much to illuminate this very significant issue.     

Interpretive structural modeling—A useful tool for technology assessment?

Interpretive Structural Modeling (ISM) is a computer based technique for helping small groups develop graphical representations of complex systems. In this paper, the rationale for the use of Interpretative Structural Modeling in activities such as technology assessment is developed and the basic concepts underlying the technique are explored. Several applications of ISM are described and from these experiences some observations are made about the nature and effectiveness of the ISM process and product. ISM was found to provide its users with a systematic and comprehensive method for integrating group judgments in the development of “first-cut‘ structural models. At the same time, however, the technique was found to be relatively inflexible and may, in some instances, inhibit group processes. Possible directions for the development of less rigid methods are suggested.     

The growth of shiftwork in the British food,drink and tobacco industries

The authors develop and estimate an econometric model of shiftworking for male, manual employees in the food, drink and tobacco industries. In the demand equations TSLS techniques are used to take account of simultaneity in the determination of shiftworking, capital intensity and plant size. Market demand variables are also incorporated in the model to allow for the distinction between ex ante and ex post decisions to work shifts. A demand variable is also incorporated in the supply equations. The results confirm the diverse economic characteristics of these industries, suggesting that inter-industry studies may conceal a considerable degree of variation at MLH level.     

A comparison of alternative methods of updating input-output coefficients

In recent years there has been a growing number of input-output models of economies ranging in scale from the rural to the national. While offering invaluable insights into the interaction of sectors within an economy, the input-output model suffers from the fact that its coefficient values are altered over time due particularly to technological change. Two of the prominent techniques designed to update these technical coefficients, the RAS and linear programming methods, are compared herein with regard to changes in U.S. national coefficients between 1963 and 1967. Suggestions for improvements to the latter method are outlined.     

Implementing a new inventory management system

Determining the type of inventory management system to use in a hospital depends as much on one's technical abilities as its does with the culture of the institution and the vendor's capabilities.