The stable and radio-isotope chemistry of southeastern Utah Basketmaker II burials: dietary analysis using the linear mixing model SISUS,age and sex patterning,geolocation and temporal patterning

The Bayesian linear mixing model SISUS is used to reconstruct reliance on maize and intake of animal protein from the stable carbon (δ¹³C) and nitrogen (δ¹⁵N) isotope values of 149 directly dated Basketmaker II burials. Maize is the primary dietary staple. δ¹³C values are also enriched by intake of yucca and wild C₄ plant foods but these resources are of minor importance in sampled diets. Animal protein intake is low and cottontail rabbits make the greatest contribution to female diets. Adolescent diets are indistinguishable from the diets of adult females and both groups are less reliant on artiodactyls than males. The δ¹³C and δ¹⁸O values of bone hydroxyapatite distinguish nursing infants and oxygen isotope values identify outsider adults relative to those local to the region where their deaths occurred. Most Utah Basketmaker II burials are contemporary with Black Mesa Lolomai phase occupations, postdating the Marsh Pass, AZ, White Dog phase. All burials in both studies were recovered from sheltered rather than open sites and reliance on maize does not increase over the temporal span of the Utah study, covering the two sigma range 415 BC–AD 322.     

A re-assessment of Basketmaker II cave 7: massacre site or cemetery context

Our ongoing investigation of early maize farming in the American Southwest has entailed stable isotope analysis and accelerator radiocarbon dating of Basketmaker II remains from sites in the Four Corners region. Here we report radiocarbon dates on a large mortuary assemblage excavated by Richard Wetherill in 1893 from a burial cave in southeastern Utah. It has long been thought that all individuals interred in Cave 7 were massacred in a single violent attack given embedded projectiles and evidence for blunt force trauma. However, accelerator radiocarbon dates on purified bone collagen (n = 96) do not lend strong support to this argument, even among the subset of individuals with clear evidence for violent injuries. Moreover, nearly 80% of Cave 7 burials examined in the study show no evidence of perimortem trauma and no adult females or subadults under the age of 12 appear to have suffered violent deaths. Rather than an anomalous single-event massacre, the Cave 7 radiocarbon dataset suggests that raiding and intra-group, male/male violence was episodic among Basketmaker groups in southeastern Utah. Population densities were relatively high and individuals interred in Cave 7 and elsewhere in the region were heavily dependent on maize agriculture, a prehistoric economic strategy typically characterized by high amplitude fluctuations in productivity. Variability in the array of grave goods accompanying Cave 7 male burials and elsewhere suggests competitive social differentiation likely heightened during periods of resource shortfall leading to intra-group conflict, raiding and perhaps ritualized acts of violence.     

Estimating a Destination-Choice Model from a Choice-based Sample with Limited Information

In most applications of multinomial logit and other probabilistic discrete-choice models, the estimation data set is either a simple random sample of the population of interest or an exogenously stratified sample. Often, however, it is cheaper and easier to sample individuals while they are carrying out the chosen activity of concern. This produces a choice-based sample, which presents important problems of estimation and inference. This paper is concerned with estimation of destination-choice models from choice-based samples when neither the aggregate market shares of alternatives nor the probability distribution of explanatory variables in the population is known. The method of Cosslett (1981) for estimating multinomial logit models from such data is summarized, and the limitations on information about choice behavior that can be recovered from the sample are explained. An empirical model of pharmacy choice in the Namur, Belgium, area is presented. It is shown that useful and important information about destination-choice behavior can be obtained from a choice-based sample, even without knowledge of aggregate market shares and the probability distribution of explanatory variables.     

The Max-Min-Min Principle of Product Differentiation

We analyze two and three-dimensional variants of Hotelling's model of differentiated products. In our setup, consumers can place different importances on each product attribute; these are measured by weights on the disutility of distance in each dimension. Two firms play a two-stage game; they choose locations in stage 1 and prices in stage 2. We seek subgame-perfect equilibria. We find that all such equilibria have maximal differentiation in one dimension only; in all other dimensions they have minimum differentiation. An equilibrium with maximal differentiation in a certain dimension occurs when consumers place sufficient importance (weight) on that attribute. Thus, depending on the importance consumers place on each attribute, in two dimensions there is a max-min equilibrium, a min-max equilibrium, or both. In three dimensions, depending on the weights, there can be a max-min-min equilibrium, a min-max-min equilibrium, a min-min-max equilibrium, any two of these, or all three.