Elimination of Source A and B Errors in p-Median Location Problems

The p-median problem is a powerful tool in analyzing facility location options when the goal of the location scheme is to minimize the average distance that demand must traverse to reach its nearest facility. It may be used to determine the number of facilities to site, as well as the actual facility locations. Demand data are frequently aggregated in p-median location problems to reduce the computational complexity of the problem. Demand data aggregation, however, results in the loss of locational information. This loss may lead to suboptimal facility location configurations (optimality errors) and inaccurate measures of the resulting travel distances (cost errors). Hillsman and Rhoda (1978) have identified three error components: Source A, B, and C errors, which may result from demand data aggregation. In this article, a method to measure weighted travel distances in p-median problems which eliminates Source A and B errors is proposed. Test problem results indicate that the proposed measurement scheme yields solutions with lower optimality and cost errors than does the traditional distance measurement scheme.     

Disaggregate Migration Behavior and the Volume of Interregional Migration

Nested multinomial logit models are used to investigate migration behavior during the 1971–74 period for a large sample of the population of Ecuador. The nested form of the model makes it possible to test hypotheses about the importance of destination characteristics in conditioning the odds for out-migration. Our empirical results indicate that the odds for migration from each origin are conditioned by the expected utilities of the available set of destinations, as well as characteristics of the origins and the personal characteristics of potential migrants. The association between destination characteristics and the frequency of out-migration allows the total volumes of migration to be adjusted to interregional differences in place-specific utilities.     

Mary McLeod Bethune's Feminism: Black Women as Citizens of the World

This article focuses on the particular moment of the 1945 United Nations charter meeting as a catalyst for a shift in Mary McLeod Bethune's feminist thought. The meeting, where Bethune served as the only African American female delegate, signalled a change in Bethune's thinking about equality for black women, so she used the founding of the United Nations as a platform to promote black women's alliances with other women of colour. Her idea was to reframe black women as citizens of the world, thus putting them in a numerical and ideological majority rather than keeping them in a minority position. Bethune has often been viewed as a reformer of race and gender issues in the early twentieth century, but a focus on her activism has hidden the intellectual contributions that she made to a form of black feminism that emerged out of her work with other clubwomen and through the United Nations in the 1920s through the 1950s. Specifically, this article argues that Bethune's intellectual work created a framework for African American women's feminism that emphasised anti-colonialism and their global alliance with other women of colour throughout the world.     

Reviews of books

Historical Archaeology -