Donald E. Lewis

The Measurement of the Occupational and Industrial Segregation of Women

The mathematical relationship between alternative measures of occupational and industrial segregation is explored. Several theorems are proven which expose some fallacies regarding the two most common measures and establish a link between them. A new index is introduced which measures the extent of the compound effect of segregation by occupation and industry. Indices of segregation are calculated from Commonwealth Census data from 1891 to 1976. Estimation of log-linear equations indicate that segregation by sex is declining; the rate of decrease, however, is slowing down and substantial changes in segregation before the year 2001 are unlikely if past trends continue.

A Linear Model of Fine Enforcement with Application to England and Wales

Fines are the most common sanction against criminal offenders in many countries. Economists have developed models for determining the optimal use of fines. Their models, however, generally abstract from problems of fine enforcement and assume that all fines are collected and that enforcement costs are zero. Criminologists and practitioners, on the other hand, have been very much aware of enforcement costs. Imprisonment for fine default is particularly costly and exacerbates the crowded prison conditions that exist in many countries. This paper extends previous economic models by dropping the limiting assumption of zero enforcement costs. The model is estimated using data from England and Wales and is used to evaluate alternative methods and levels of fine enforcement.

Comparative Quit Rates of Men and Women

Observed differences in quit rates of men and women have little value in explaining the wage gap between the sexes. It is hypothesised that because men and women quit for different reasons, employers believe the quit rate differential to be greater than it is. This hypothesis is substantiated by inter views with personnel directors; the results indicate that they significantly under estimate the quit rate of their male employees and over-estimate the quit rate of their female employees. If employers act on these inaccurate assessments, they are likely to discriminate against women when making decisions about hiring, training and promoting their staff.

The optimal parole period

Abstract A probabilistic, theoretical model is developed for determining the optimal length of parole. Optimal parole periods are then calculated for alternative parameter estimates based on empirical data. The model, primarily designed for property crimes, can be extended to other offences.

The Economics of Crime: A Survey

The economics of crime has become a substantial body of analysis in the past 20 years. Evidence for this is provided by the number of books and articles in quality journals and the increasing attention criminologists and policy makers are paying to the work of economists. This article provides a sample of the problems addressed and the theoretical and empirical contributions. Particular attention is paid to the work of Australian economists.

Ocupational segregation, labour force participation and the relative earnings of men and women

A model of the labour market is developed in which particiaption rates of men and women,wages rates of men and women and occupational segregation are determined simultaneously. The model is estimated using cross-sectional data from Australia. The most important empirical results are that (a) particiaption rates,wage rates and occupational segregation should be viewed as being simultaneously determined,(b) differences in male and female labour-force attactment and human capital attainment are important determinants of the gender composition of occupations and (c)there is little direct evidence in this study to support discrimination-based theories of occupational segregation.

The Measurement and Interpretation of the Segregation of Women in the Workforce

* Senior Lecturer, Department of Economics, University of Wollongong, PO Box 1144, Wollongong, NSW 2500. I would like to thank Marie Paterson for her helpful comments and Pauline Doyle for her excellent research assistance. In my 1982 article in the JIR, I calculated indices of occupational and industrial segregation based on Commonwealth census data from 1891 to 1976. The index used to measure occupational segregation was:

Earnings differentials and occupational segregation by gender: A simultaneous equations approach

Abstract Models of male/female earnings differentials which include explanatory variables such as occupational distribution and participation rates are criticized for failing to account for the simultaneity of the relationships involved. An alternative, eight-equation model of earnings differentials, participation differentials and occupational segregation is developed. Application of the model to Australian census data is discussed.

Regional trade flows of manufactured products

Little is known about regional trade flows in the United States. Using tonnage data from theCensus of Transportation, this study develops dollar estimates of the trade of manufactured products between the census regions. The technique utilized makes it possible to construct import-export matrices for 19, two-digit S.I.C. industries for the years 1963 and 1967. Total imports, exports, and resulting balances of trade are estimated for each census region. It is found that, quantitatively, interregional trade is much more important to the various regions than international trade is to the United States.

Do Students Benefit From Supplemental Instruction

Peer assisted study sessions (PASS) are a type of supplemental instruction (SI) that provide students with out-of-class study review sessions with a group of peers. A student, who has successfully completed the subject and acts as a mentor, facilitates the voluntary sessions. Results of the PASS program at the University of Wollongong have been quite positive in that students, on average, who attend more PASS, achieve higher marks. However, a simple comparison does not control for self-selection bias. We control for self-selection in two ways. Firstly, we use Heckmans two-stage correction technique to analyze the 2002 cohort. Secondly, students in the 2003 cohort were randomly allocated into three groups of equal size: - A control group that was allocated to normal tutorials with standard class sizes and ineligible to attend PASS - A group that was eligible to attend PASS and had normal tutorials of standard sizes - A group that was ineligible to attend PASS but allocated to normal tutorials with smaller class sizes. The results of both methods are consistent and indicate the PASS program has a positive impact on the academic performance of students after correcting for selection bias.