Environment and Planning A: Economy and Space

It is argued that J H von Thünen was a realist who deliberately used unrealistic assumptions to pursue a true account of a major aspect of the determination of agricultural land-use patterns. The assumptions of the simplest model of concentric rings are examined to show that this highly unrealistic model deserves a realist interpretation: the idealising assumptions serve the purpose of neutralising the impact of a number of factors on the land-use pattern and thereby help focus on the causal contribution of one major factor, namely distance from the market. It is von Thünen's conviction that this factor and its causal contribution are real rather than fictional, and that his basic model truthfully captured them. The potential truth of von Thünen's simplest model does not require that its assumptions are true nor that the representation of the resulting land-use pattern is true. This reading of von Thünen's theory is contrasted with the traditional fictionalist ‘as-if’ interpretation of Der isolierte Staat espoused by Hans Vaihinger, Peter Hall, and others. It is pointed out that economists and geographers both hold notions of realism that fail to accommodate von Thünen's realism. Although economists tend to conflate realism and realisticness and therefore fail to understand that realism is compatible with the use of unrealistic assumptions, human geographers have adopted highly specific ideas of realism that fail to do justice to von Thünen's theory. Because much of theorising in both disciplines follows the Thünian strategy, there is an important lesson to be learnt both for supporters and for opponents of that strategy.

Geographical economics is a recent approach in economics aiming at introducing the ‘role of space’ into the mainstream of the discipline. Though interested in similar issues, economic geographers strongly criticise geographical economics. This paper puts such criticisms under scrutiny, taking Ron Martin's 1999 influential contribution as representative. A philosophically informed analysis of these criticisms brings forth possible misunderstandings in the dispute and hence assists both parties by making criticism and responses more incisive. If, as it seems at least in some geographers’ view, economic geographers are concerned with mechanisms and processes different from the abstract general economic mechanisms analysed by geographical economists, then complementarity between the two approaches turns out to be a possibility. This challenges both economic geographers and geographical economists because it asks them to go beyond methodological differences and establish whether the general and abstract mechanisms identified by the latter are compatible with those identified by the former. If so, further investigation on how they combine as to bring about real-world agglomeration is needed.

The autologistic model describes binary correlated data; its spatial version describes georeferenced binary data exhibiting spatial dependence. The conventional specification of a spatial autologistic model involves difficult-to-nearly-impossible computations to ensure that appropriate sets of probabilities sum to 1. Work summarized here accounts for spatial autocorrelation by including latent map pattern components as covariates in a model specification. These components derive from the surface zonation scheme used to aggregate attribute data, to construct a geographic weights matrix, and to evaluate geographic variability. The illustrative data analysis is based upon field plot observations for the pathogen Phytophthora capsici that causes disease in pepper plants. Results are compared with pseudolikelihood and Markov chain Monte Carlo estimation techniques, both for the empirical example and for two simulation experiments associated with it. The principal finding is that synthetic map pattern variables, which are eigenvectors computed for a geographic weights matrix, furnish an alternative, successful way of capturing spatial dependency effects in the mean response term of a logistic regression model, avoiding altogether the need to use other than traditional standard techniques to estimate model parameters.

This paper explores three aspects of the au pair migration experience, through a case study of Slovakians, mostly but not all women, who have returned from sojourns in the United Kingdom. First, it argues that au pairs are distinctive from other migrants working in domestic service. Their positions have to be understood in terms of a particular regulatory framework, temporal restrictions, living-in conditions, and the blurring of rights and responsibilities. Second, there is a need to consider the full cycle of migration. Returned au pairs have been able to commodify many aspects of their UK experiences, despite the constraints of relatively short visits, and the household and care work allocated to them. Third, understanding au pair migration as being socially and spatially constituted provides greater insights into their experiences and outcomes.

Environmental justice research in the United States has coalesced around the notion that visible-minority status, along with socioeconomic position (SEP), conditions exposure to environmental health hazards. In the context of long-standing debates over Canada–USA urban differences, we address the question of whether racial gradients exist in air pollution across Hamilton, Canada. Monitored air quality data are spatially interpolated with a kriging algorithm. These interpolated exposures are statistically correlated with 1996 data at the census tract scale, with the aid of multivariate and spatial techniques. The proportion of Latin-Americans in a census tract is positively associated with pollution exposure, even after control for many SEP variables. In contrast, Asian-Canadians are negatively associated with air pollution, and Black-Canadians show no clear correlation at all. Thus, the faces of environmental racism in Canada seem more varied and nuanced than in the USA. Given the immigrant basis of visible minorities in Canada, we argue that Hamilton (and the Canadian city generally) may represent new dimensions of environmental racism driven by economic status at time of entry. In drawing on similar findings in the USA and the United Kingdom, the authors conclude that environmental racism appears present in all jurisdictions, but that the nature and extent of disproportionate exposure differ between countries.

This study analyzes retrospective data on telecommuting and residential and job location changes over a ten-year period, from 218 employees (62 current telecommuters, 35 former telecommuters, and 121 people who had never telecommuted) of six California state government agencies which had actively participated in the well-known pilot program of 1988–90. We compare estimates of the total commute person-miles traveled by telecommuters with those of nontelecommuters, on a quarterly basis. Key findings include the following. One-way commute distances were higher for telecommuters than for nontelecommuters, consistent with prior empirical evidence and with expectation. Average telecommuting frequency declined over time; several explanations are proposed, but cannot be properly tested with these data. The first two findings notwithstanding, the average quarterly per capita total commute distances were generally lower for telecommuters than for nontelecommuters, indicating that they telecommute often enough to more than compensate for their longer one-way commutes. We cannot say from these results whether the ability to telecommute is itself prompting individuals to move farther away, or whether telecommuting is simply more attractive to people who already live farther from work for other reasons. Even if the first is true, however, and telecommuting is the ‘problem’, it also appears to be the solution: that is, it enables people to achieve a desired but more distant residential location without a net increase in commute travel.