计量经济分析 = Econometric analysis

Research in transportation, urban design, and planning has examined associations between physical environment variables and individuals' walking and cycling for transport. Constructs, methods, and findings from these fields can be applied by physical activity and health researchers to improve understanding of environmental influences on physical activity. In this review, neighborhood environment characteristics proposed to be relevant to walking/cycling for transport are defined, including population density, connectivity, and land use mix. Neighborhood comparison and correlational studies with nonmotorized transport outcomes are considered, with evidence suggesting that residents from communities with higher density, greater connectivity, and more land use mix report higher rates of walking/cycling for utilitarian purposes than low-density, poorly connected, and single land use neighborhoods. Environmental variables appear to add to variance accounted for beyond sociodemographic predictors of walking/cycling for transport. Implications of the transportation literature for physical activity and related research are outlined. Future research directions are detailed for physical activity research to further examine the impact of neighborhood and other physical environment factors on physical activity and the potential interactive effects of psychosocial and environmental variables. The transportation, urban design, and planning literatures provide a valuable starting point for multidisciplinary research on environmental contributions to physical activity levels in the population.

Environmental correlates of walking and cycling: Findings from the transportation, urban design, and planning literatures

The authors examine the implications of electronic shopping for consumers, retailers, and manufacturers. They assume that near-term technological developments will offer consumers unparalleled opportunities to locate and compare product offerings. They examine these advantages as a function of typical consumer goals and the types of products and services being sought and offer conclusions regarding consumer incentives and disincentives to purchase through interactive home shopping vis-à-vis traditional retail formats. The authors discuss implications for industry structure as they pertain to competition among retailers, competition among manufacturers, and retailer-manufacturer relationships.

Interactive home shopping: Consumer, retailer, and manufacturer incentives to participate in

New Patterns of Management.

The sustainable mobility paradigm

This paper contests the conventional wisdom that travel is a derived demand, at least as an absolute. Rather, we suggest that under some circumstances, travel is desired for its own sake. We discuss the phenomenon of undirected travel – cases in which travel is not a byproduct of the activity but itself constitutes the activity. The same reasons why people enjoy undirected travel (a sense of speed, motion, control, enjoyment of beauty) may motivate them to undertake excess travel even in the context of mandatory or maintenance trips. One characteristic of undirected travel is that the destination is ancillary to the travel rather than the converse which is usually assumed. We argue that the destination may be to some degree ancillary more often than is realized. Measuring a positive affinity for travel is complex: in self-reports of attitudes toward travel, respondents are likely to confound their utility for the activities conducted at the destination, and for activities conducted while traveling, with their utility for traveling itself. Despite this measurement challenge, preliminary empirical results from a study of more than 1900 residents of the San Francisco Bay Area provide suggestive evidence for a positive utility for travel, and for a desired travel time budget (TTB). The issues raised here have clear policy implications: the way people will react to policies intended to reduce vehicle travel will depend in part on the relative weights they assign to the three components of a utility for travel. Improving our forecasts of travel behavior may require viewing travel literally as a “good” as well as a “bad” (disutility).

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How derived is the demand for travel? some conceptual and measurement considerations

Telecommunications and travel relationships: a review

There is growing concern about the negative environmental and energy effects caused by transportation systems and related land-use patterns. Travel and land-use are a function of one another, therefore it is often hypothesized that changing urban structure can result in changes in energy consumption. A popular view suggests that there is a strong negative correlation between urban density and energy consumption. This implies that increasing density will result in a reduction in energy consumption [Cities and Automobile Dependence: An International Sourcebook, Avebury Technical, Great Britain, 1989]. Using Co-Plot, an innovative multivariate statistical technique, this research crystallizes some of the relationships between density and energy consumption in western cities. The method is applied on Newman and Kenworthy’s data, leading to the conclusion that there is no direct impact of total urban density. Instead several other relationships between energy consumption and density attributes can be identified.

Urban density and energy consumption: a new look at old statistics

Innovations in telecommunications technology increase the possibilities of working from the home. Implications of work-at-home arrangements for the individual's quality of working life are discussed. Included are discussions of several major aspects of the work experience relevant to quality of working life, analyses of the differences along these aspects between working at home and working at a normal workplace, and speculation about the possible consequences for the individual of the transfer of jobs from employers” premises to employees' homes.

Work-At-Home and the Quality of Working Life

This paper begins to operationalize a previously published conceptual model of the individual decision to telecommute. Using survey data from 628 employees of the City of San Diego, hypothesized drives to telecommute and constraints on/facilitators of telecommuting are measured. A binary logit model of the preference to telecommute from home is estimated, having a ϱ2 of 0.68. The explanatory variables include attitudinal and factual information. Factor analysis is performed on two groups of attitudinal questions, identifying a total of 17 (oblique) factors which can be classified as drives and constraints. Additional measures are created from other data in the survey, usually objective sociodemographic characteristics. Variables representing at least four of the five hypothesized drives (work, family, independence/leisure, and travel) are significant in the final model. Variables from four of the ten groups of constraints (Job suitability, social/professional and household interaction concerns, and a perceived benefit of commuting) are significant, primarily representing internal rather than external constraints. The results clearly demonstrate the importance of attitudinal measures over sociodemographic ones, as the same demographic characteristics (such as the presence of children, commute time) will have different effects on preference for different people.

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Ilan Salomon

Papers

How derived is the demand for travel? some conceptual and measurement considerations

Telecommunications and travel relationships: a review

Urban density and energy consumption: a new look at old statistics

Work-At-Home and the Quality of Working Life

Modeling the desire to telecommute: The importance of attitudinal factors in behavioral models