Suchergebnisse

Before the iron horse -- Arrival of the railroads -- Critical mass -- Bypassing Chicago -- Shaping Chicago -- The suburbs -- Travelers and terminals -- The bottleneck -- The railroad supply industry -- Dominance, reform, and regulation -- Railroad crossings -- Decline and decentralization -- Liquidation, consolidation, and diversification -- Redevelopment

I analyze investment and pricing incentives in a differentiated products framework with uncertain demand. Firms choose production capacities before observing demand and choose prices after demand is realized. Unlike previous models, when firms are identical, symmetric pure-strategy equilibria exist, even in the presence of very low capacity costs. The equilibrium outcomes are significantly different from the equivalent Cournot model. Firms choose to underutilize their capacity at times of low demand, and hold more capacity than predicted by Cournot. I show with a simple policy example that even the sign of the comparative statics may differ between the two models.

There have been growing similarities between broadcasting issues in Canada and Europe. Some issues, including the emergence of private broadcasting and concerns about American broadcasting, became prominent in Europe decades after they were evident in Canada. In both contexts, historical and contemporary debates about broadcasting issues have been tied to three discourses on communication technologies. This article contends that broadcasting policy debates in Canada and Europe can usefully be interpreted through a theoretical model that addresses technological determinism, technological democracy and technological nationalism. The model places the discourses in the context of struggles between dominant agents (private companies, governments or supranational institutions) and subordinate agents (including various social movements). The model shows how connections between the discourses help to secure the hegemony of powerful groups. However, the model also identifies contradictions within the discourses and compromises involving the discourses. Both are associated with opposition from less powerful groups.

Migration is a universal but poorly understood human behavior, and new analytic tools for studying migration are badly needed. In this article, I describe a new computer simulation method for migrating human populations, which moves simulated human actors" on a lattice of points according to simple probability rules. The method includes models of birth, death, crowding, and competition, as well as of migration. Simulations are developed for a number of specific problems, including migration into empty continents, the effect of competition and migration on the spatial distribution of populations, the effect of biased migration on urban population structure, and the distribution of city sizes determined by migration. Direct comparison of simulations with measured population distributions demonstrates the plausibility of the models. The simulations suggest that seemingly complex problems of human space‐time population dynamics may be resolved into simple behavioral rules and that migration phenomena can be subjected to scientific analysis. [Key words: migration, computer simulation, random walk, urban structures]