THE GRAVITY MODEL AND HIERARCHICAL SPATIAL SYSTEMS: THEORETICAL AND EMPIRICAL OBSERVATIONS

The gravity model in its basic forms postulates that the volume of interaction between two places will be positively related to the populations (masses) of the two places and inversely related to their distance apart. Although it is not strictly speaking a hierarchical model, it is often used to explain flows among places that constitute a hierarchical spatial system. This paper is specifically concerned with the effect of hierarchical spatial structure on the performance of the gravity model. Accordingly, I will examine first the effect of hierarchical structure on the volume of interaction between places and second the degree to which the gravity model incorporates these hierarchical effects. Third, suggestions will be made for the improvement of the gravity model's performance by an explicit incorporation of a hierarchical element. The performance of the gravity model will be examined for both one-way and two-way flows between places.     

THE SPATIAL STRUCTURE OF HIERARCHICAL INTER-URBAN SYSTEMS: EQUILIBRIUM AND OPTIMUM*

In this paper, I model a simple hierarchical inter-urban system in which the location of business firms is considered together with the determination of residential land-use patterns. By supposing a spatial externality between the business firms and all the residents of the region, three spatial structures are obtained: monocentricity, multicentricity, and a separate pattern where cities are spatially split with an agricultural land existing between them. It is also shown that the spatial structures of monocentric and multicentric patterns formed by the market principle tend to be more concentrated than the optimum.     

A SPATIAL MULTIVARIATE COUNT MODEL FOR FIRM LOCATION DECISIONS

This paper proposes a new spatial multivariate model to predict the count of new businesses at a county level in the state of Texas. Several important factors including agglomeration economies/diseconomies, industrial specialization indices, human capital, fiscal conditions, transportation infrastructure, and land development characteristics are considered. The results highlight the need to use a multivariate modeling system for the analysis of business counts by sector type, while also accommodating spatial dependence effects in business counts.     

SPATIAL ECONOMIC INTERDEPENDENCE IN AN URBAN HIERARCHY SYSTEM

ABSTRACT. This paper develops a model to examine the economic interaction between central places and their hinterlands. The model allows interindustry linkages and upward trade flows in an urban hierarchy system. Trade balance equilibrium between hierarchical levels is established by direct mutual interlevel trade, rather than by indirect trade via the rural sector. The economic base multipliers generally increase with city size but occasionally they could be smaller than those of lower places. A continuous urban hierarchy is formed due to their relative location within the system, not to unspecified randomness.     

TARIFF PROTECTION IN AN OPEN SPATIAL ECONOMY*

Spatial pricing models have been used to illustrate a tariff's asymmetric effects on consumers located at different points in the protected economy, and to demonstrate that the optimum tariff for a small open spatial economy may be positive. In these models, the distribution of households has been taken as uniform and fixed. We extend the spatial model by allowing households to optimally locate and consume variable amounts of land, as well as the domestic- or foreign-produced good. Land consumption, location rents, and the distribution of consumers are endogenous, responding to tariff-induced changes in the delivered prices of the domestic and foreign goods. Within this limited general equilibrium framework, a neoclassical result resurfaces: from the perspective of private consumers, the optimum tariff in a small open economy is zero. The possibility of a positive optimum tariff, however, may remain intact in a more integrated model where domestic profits and tariff revenues are redistributed within the spatial economy.     

A RESIDENTIAL ENERGY MARKET MODEL: AN ECONOMETRIC ANALYSIS*

This paper develops a multisector residential energy policy model. This model hypothesizes that household energy behavior is affected by conditions in the housing, the mortgage finance, and the energy markets. The relationships encompassed by the model are specified with 32 single and simultaneous equations and tested with quarterly data drawn from behavior in Delaware. After the testing and evaluation of the model for its statistical performance, thereafter, three energy policies are simulated a 5 percent residential energy consumption tax, a set of conventional insulation requirements for all new housing, and a passive solar-installation requirement for all new housing. These policy choices are evaluated in terms of their impact on energy consumption, prices, demand and size of different types of housing permits, and mortgage financing. Finally, the economic and social implications of these policy impacts are discussed.     

A NEOCLASSICAL MODEL OF HOUSING QUALITY GROWTH AN INTERPRETATION*

The paper interprets a neoclassical model of quality growth in relation to housing technology, reinvestment choice, growth of the stock of shelter, growth with and without architectural design progress, and analyses of the golden rule of quality accumulation in the housing sector.