NETWORK EQUILIBRIUM MODELS OF URBAN LOCATION AND TRAVEL CHOICES: A RETROSPECTIVE SURVEY*

ABSTRACT The origins and development of the network equilibrium problem are traced and interrelated. Two principal formulations are considered the network equilibrium problem with variable travel demand, and the combined model of trip distribution and traffic assignment. The relation of these models to subsequent developments concerning mode choice, residential location, estimation of origin-destination tables from link flows and stochastic route choice are then reviewed.     

MEASURING THE EFFECT OF COST VARIATION ON INDUSTRIAL OUTPUTS*

ABSTRACT. This paper introduces the household interactive variable input-output (HIVIO) model to measure the effect of cost variation on industrial outputs. The model produces a variety of cost elasticities that separate out impacts on industrial prices, imports, and outputs, with “own” and “cross” elasticity components. Like the conventional input-output multipliers, these cost elasticities can be useful parameters to evaluate the substituting behavior of firms and consumers. By using the 1980 Korean input-output transactions table, we find the wage and import price effects on industrial prices, outputs, and import demands.     

Incorporating the effects of spatial structure in discrete choice models of migration

Discrete-choice theory and logit models are evaluated for their usefulness in analyzing migration patterns in a zonal system. The authors "argue that spatial effects and more specifically the relative location of zones are not taken into account in such analyses. We, therefore, introduce a measure of spatial structure and advocate its usage as a predictor of migration in such models. In an example of intrametropolitan migration in Toronto [Canada], we demonstrate that this variable is not only significant but also it improves the performance of all the other variables with the greatest impact on the distance between zones. In addition, inclusion of this variable improves the overall performance of the model in terms of residuals."     

Late pleistocene human adaptations in eastern North America

Eastern North America in late Pleistocene times was characterized by two major environmental regions: a periglacial tundra or open spruce parkland and an extensive complex boreal/deciduous forest in the unglaciated, lower latitudes. These environments selected for different adaptive strategies on the part of human foraging groups—known archaeologically as Paleoindians. Those in the tundra and tundra-forest region were highly mobile, possibly specialized hunters, exploiting caribou; those in the forest were generalists, exploiting a variety of subsistence resources with a less mobile settlement system. There is little evidence in either area for hunting of Pleistocene megafauna. These differences in adaptive strategies are reflected in the record of sites and isolated fluted points scattered throughout the region, as well as aspects of tool technology, function, and patterns of stone use.