The establishment of the presence and group classification of sperm in mixed stains by isoelectric focusing

The article deals with experimental data on design of the method used for detection of sperm, blood and vaginal secretions according to isoelectric points of acid phosphatases, differential diagnosis of ABO group antigens in "mixed" stains as well as detection of phenotype of red cell acid phosphatase by isoelectric focusing method.     

The population in a sociopolitical system in crisis: Mexico before the Revolution

The author reviews some of the literature on the Mexican Revolution in order to assess the impact of demographic change on the outcome of that conflict. Consideration is given to urbanization, spatial distribution, literacy, industrial growth and the employment opportunities it provided, and land conflicts caused by population growth. (SUMMARY IN ENG)     

Work,fertility, and the status of women in Mexico

Among the major transformations affecting Mexican women in recent decades were their growing participation in the labor market and the fertility decline that began in the 1970s with widespread access to contraception. Data from 3 major Mexican fertility surveys, employment surveys, and censuses are used to analyze changes in female employment and their determinants during the years of economic recession in the 1980s. The main characteristics of the Mexican fertility decline are described, and the relationship between fertility and female employment before and during the economic recession is scrutinized for different social sectors. Suggestions for research on the affects of these changes on the social condition of Mexican women are then presented. The proportions of Mexican women over 12 years old who declared themselves economically active increased from 16% in 1970 to 21% in 1979 and 32% in 1987. Until the 1970s the majority of employed women were young and single or childless. But a clear increase occurred between 1976-87 in the economic participation of older women in union. Economic participation of low income and less educated women increased as they sought work or created their own in response to deteriorating living conditions during the recession. Young women with intermediate or higher educational levels did not increase their relative presence in the labor market in the same period. The marked increase in economic participation of less educated women in union with small children was accompanied by a significant increase in manual occupations. Between 1982-87, the proportion of women aged 20-49 in nonsalaried manual occupations rose from 7.6% to 18.5%. Mexico's fertility decline has been well documented. The total fertility rate declined from 6.3 in 1973 to 3.8 in 1986, while the percentage of women in union using a contraceptive method increased from 30.2 in 1976 to 52.7 in 1987. Fertility differentials have been declining but are still considerable. The inhibitory influence of children on female labor force participation in Mexico is clear, but in the years of economic recession the most notable increase in female workers was in women with 3 or more children of whom the youngest was under 3. It appears that the influence of children on women's employment depends on the socioeconomic status of the woman as well as on the dynamism or sluggishness of the labor market. Research is needed on the significance of changes in fertility and female employment for women's status in Mexico. Several recent works have presented results of microsocial analyses of the ways in which women experience changes in their lives resulting from fertility and employment decisions. A methodological strategy for studying these changes and their influence on women's status should focus on comparisons between different generations and birth cohorts, different types of employment, and different socioeconomic statuses. Both macrosocial and microsocial forms of analysis are needed to provide a full picture.     

The link between demographic events: a study of nuptiality patterns

The author examines links between the timing of various major life events (including women's age at marriage and the spacing of children) and the economic and urban development of a society, using Mexico as an example. The focus is on marriage patterns. She finds that nuptiality influences rural-urban migration for women, as do age and socioeconomic factors and husband's employment status. Data are from the Mexican Fertility Survey for the period 1976-1977. (SUMMARY IN ENG)     

Tollison costs and technological innovation: The case of environmental regulation

This paper departs from the Tullock cost paradigm that views competition for monopoly privilege as a welfare-inimical process that wastefully dissipates preexisting producers' surplus and, occasionally, leads to inefficient increases in costs and counterproductive uses of scarce resources. The potential availability of rent-seeking may bring about the elimination of inefficient regulatory regimes that retard or prevent the introduction of cost-reducing innovations. Air quality management is but one area in which innovation rent-seeking holds promise for concrete welfare gains. Researchers may wish to focus on institutional mechanisms designed to overcome the transactions costs and free rider disincentives to the formation of a coalition to seek innovation rents. An example of such a mechanism might be a joint venture that requires all venture members to engage in lobbying and to contribute to collective research efforts. These unaddressed questions await future research.The authors are grateful for the insightful comments of Gordon Tullock, Robert D. Tollison, Michael T. Marlow and J.R. Clark. The usual caveats apply. The views expressed herein are solely those of the authors and should not be taken to represent the views of their employers.