An infinite class of PBIB designs

In this paper, an infinite class of partially balanced incomplete block (PBIB) designs of m+1 associate classes is constructed through the use of a series of row-orthogonal matrices known as partially balanced orthogonal designs (PBOD) of m-associate classes. For the purpose, a series of PBOD is obtained through a method described herein. An infinite class of regular GD designs is also reported.     

Wirth,Whiskey, and WASP's: Some Consequences of Community Size for Alcohol Use*†

Several themes in Wirth's “Urbanism as a Way of Life” generate the prediction that alcohol use (versus nonuse) will be more widespread among residents of urban areas. Multiple regression analysis of data from two recent national polls (1966, 1968) reveals support for this prediction. With eight other key sociological variables simultaneously controlled, the greater the urbanism of a community (measured in terms of community size), the greater the proportion of alcohol users it contains. To make certain that this association is due to urban conditions (as opposed to merely the absence of rural forces which encourage abstinence), the effects of rural forces are reduced by omitting the most rural categories of the community size measure of urbanism, and the data are reexamined. The association still persists, basically because of the larger proportion of middle to upper status, white, and Protestant alcohol users in the more urban areas.     

The end of rapid increase in the use of oral anovulants? Some problems in the interpretation of time series of oral use among married women

Several problems in the interpretation of time series of oral anovulant usage are discussed, among them the shifting marriage-duration distribution over time. Standardization fails to negate the conclusion that the rate of increase in the proportion of women using orals has slackened since January 1966. Separate analyses by duration-specific rates of use and by marriage cohorts show that the two factors sustaining the initial spectacular growth rate in the use of orals-the ever—higher initial use rates of new marriage cohorts and the rapid adoption of orals among earlier cohorts at later durations—have lost their sustaining force. Further analysis indicates that concern over the pill as a health hazard is a major deterrent to substantial increase in oral usage. A final distribution of women by risk status with respect to oral use, and current and prospective oral use, shows that under present circumstances the maximum oral use rate will be considerably less than unity.     

Son survivorship motivation and family size in India: A computer simulation

Abstract Many sociologists and demographers have argued that the comparatively large families of six to eight children found in rural India to-day result from ignorance of family planning methods, from tradition, and from passive indecision; and that large reductions in the Indian growth rate to Western levels would occur spontaneously if each Indian family were given access to birth control facilities, materials and information. On the other hand, it has been maintained that large family sizes are functional for rural families in India and other developing countries; and that they result from conscious or unconscious choice based upon enlightened self-interest.     

Methods for the analysis of mortality risks across heterogeneous small populations: examination of space-time gradients in cancer mortality in North Carolina counties 1970–75

A method of analyzing mortality rates in heterogeneous populations is presented. This method, appropriate for the investigation of mortality rates in small geographic areas (e.g., counties) where the forces of mobility operate to selectively “package” persons, is applied to the determination of whether a spatial west-east gradient in cancer mortality rates existed in North Carolina over the period 1970 to 1975. A significant gradient (as well as a significant temporal trend) is determined to exist in the data, though only for particular race, age and sex-specific demographic groups. Several alternate hypotheses are presented to explain the existence of the spatial gradient in these particular demographic groups.