The Strategic Choice of Location and Transport Mode in a Successive Monopoly Model

This work emphasizes the incentives for vertical integration in a spatial model. A downstream monopoly will both strategically increase its transport costs and locate inefficiently relative to its customers. This forces the upstream monopolist to lower its input price rather than permit sales to decline. The excess costs and the inefficient location lower total profit in the vertical stream generating an incentive for vertical integration.     

Leaf galls on Dicroidium hughesii (Feistmantel) Lele from the Triassic of India—a new record

Disc-like galls are reported on the Triassic corystosperm leaf Dicroidium hughesii (Feistmantel) Lele from the Parsora Formation of South Rewa Gondwana Basin, central India. Although there have been numerous reports of arthropod–plant interactions from Permian and Lower Cretaceous successions, this is the first unequivocal report of arthropod–plant interactions from the Triassic succession of Peninsular India. The new record adds to global evidence that arthropod herbivory and gall formation, in particular, had rediversified by the Late Triassic in the wake of the end-Permian mass extinction.     

Location Equilibrium for Cournot Oligopoly in Spatially Separated Markets

Consider a two-stage non-cooperative Cournot game with location choice involving n≥ 2 firms each with several facilities. There are m≥ 2 spatially separated markets constituting the vertices of a network. Each firm first selects the locations of their facilities and then selects the quantities to supply to the markets to maximize its profit. There exists a Nash equilibrium in the quantities offered by each firm at the markets. Furthermore, when the demand in each market is sufficiently large, each firm chooses to locate its facilities only at vertices. With linear demand in each market, there exists a Nash location equilibrium.     

Product Differentiation and Location Choice in a Circular City*

Abstract. The paper analyzes spatial competition among firms that sell substitute and/or complementary products. The firms first choose locations on the perimeter of a circular city and then compete in quantities (à la Cournot). Both linear and convex (quadratic) transport costs are considered. In general, multiple location equilibria are encountered. Complete agglomeration, partial agglomeration, and complete dispersion are possible. Convex (quadratic) transport cost substantially shrinks the set of equilibria obtained under linear transport cost. In general, the results obtained for a larger number of firms selling complementary products are strikingly different from those obtained under a duopoly.     

Seismic Behavior of RC Bridge Piers under Bidirectional Excitations: Implications of Site Effects

Seismic demand of structures may be potentially magnified due to bidirectional shaking. This may also be strongly influenced by the amplification and/or attenuation of motions due to local site conditions. Current investigation examines the implications of these two aspects collectively. A code-designed reinforced concrete pier has been analyzed under recorded accelerograms and their derivatives from 1-D site analysis. Magnification in peak and cumulative responses due to bidirectional shaking may be sensitive to record-to-record variability. However, such magnification remains relatively stable across site characteristics. Combination rules are shown adequate to estimate peak deformation and deficient for cumulative demand irrespective of the site conditions.