A Note on Applying the Gravity Rule to the Airline Hub Problem

In this note we propose a new model for the airline hub selection problem. Passengers use a hub on the way to their destination. We apply the objective of minimizing the total miles traveled by passengers. This formulation can be used as the basis for other objectives also.     

A Threshold-Satisfying Competitive Location Model

In this paper we consider a location model based on the threshold concept. We find the best location such that the probability of revenue falling short of the threshold is minimized. This objective is appropriate when a firm will not survive if its revenue falls below a known threshold. A new store is to be located. Demand is not deterministic but rather has a statistical distribution. We seek the location at which the probability that the revenue (expressed as market share attracted by the new store) is below a given threshold is minimized. The model is formulated and solved, and computational results are given.     

Social Identity and Ethnic Interaction in the Western Pueblos of the American Southwest

With the increasing realization of the frequency of migration in prestratified societies, our understanding of ethnic interaction needs to become more sophisticated. This paper discusses ethnic interaction in prestratified societies on a theoretical level by examining currently used models based on Barth's concepts of interaction (Barth, F., Ethnic Groups and Boundaries, Little, Brown, Boston, 1969, pp. 9–39) and Bourdieu's concept of habitus (Bourdieu, P., Outline of a Theory of Practice, Cambridge University Press, Cambridge, 1977). These current models are flawed, and an alternative model relying on reflexive decisions by agents who are constrained by their place within the existing social structure is presented. This model is then used to examine ethnic identity in Western Pueblo societies in three areas of central Arizona: Point of Pines, Grasshopper, and Silver Creek. All three areas were locations of prehistoric migration and subsequent interaction between migrants and indigenous peoples. However, the nature of the interaction differed considerably, with ethnicity being emphasized in some places, de-emphasized in others, and ignored all together in still others.     

External validity of hedonic price estimates: Heterogeneity in the price discount associated with having Black and Hispanic neighbors

We examined the hedonic price of neighborhood racial composition across a sample of 180 US housing markets and compared heterogeneity in results. Statistically significant estimated price elasticities calculated at the mean ranged from ?0.61 to 0.2 and ?0.26 to 0.21, for increases in Black and Hispanic neighborhood proportion, respectively. Hedonic price discounts for Black neighborhoods were greater when land supply was more inelastic, when the land value share of the housing cost was greater, and in the southern portion of the United States. Hedonic price discounts associated with Hispanic neighborhoods exhibited no patterns relative to geography or housing supply factors.     

Identifying grinding,scoring and rubbing use-wear on experimental ochre pieces

Ochre pieces were used experimentally for a variety of grinding, scoring and rubbing activities to record and compare the use-wear markings that each activity creates on the ochre piece. Ochre that is ground on coarse or fine-grained slabs develops parallel striations that cover the surface of the piece. The striations have unfrayed ends. Grinding is the only activity that results in significant changes to the surface shape of the ochre, producing a plane. When ochre is scored either to create a deliberate design or to produce powder, the grooves that form often do not reach all the edges of the used surface and they regularly have frayed terminations. This demonstrates that the incisions were created by multiple scoring strokes. When ochre is scored to manufacture ochre powder the incisions that are generated are parallel groups of grooves with erratically oriented grooves as well. Bone and wooden tools are soft and they therefore do not generally create obvious incisions on ochre pieces. Grooves created through grinding on a slab or scoring with a stone tool have microstriations within them and they show a range of profile shapes. The most common use-wear from rubbing ochre on animal hide, human skin, human hair and wood is smoothing, edge rounding and polish, although incisions and microstriations also occur occasionally. Residues are often left on an ochre piece after rubbing or scoring with organic materials. The comparative collection of macro- and microscopic use-wear marks from experimentally ground, scored and rubbed ochre is useful as an aid to classifying archaeological collections of ochre.