Igor Vojnovic

This paper presents a data-driven agent-based model that simulates the weekly grocery shopping behavior of disadvantaged consumers in highly segregated lower eastside neighborhoods of Detroit, Michigan. We focus on neighborhoods experiencing severe disinvestment to analyze the shopping behavior of residents after all major regional and national supermarket chains abandoned the city. The presented model is unique in that it utilizes detailed shopping behavior data collected to examine travel in marginalized communities, specifically among residents in severe poverty who are often overlooked in the travel behavior literature. The research shows that in extreme socio-economic decline, sociodemographic variables (such as class) can become more relevant than the built environment (land-use mix, density, and street connectivity) in determining access and influencing mobility. After identifying unique groups of household agents, we design rules that utilize probability distributions generated from survey responses. The decision-making of agents that emulate households is habitual rather than utility driven. Modeled behavior is designed based on stated preferences, which may contradict premises such as the “shortest distance to the nearest shop” approach, a common assumption in the literature. We also report on three what-if scenarios to evaluate how major population changes would affect the results.

Only a handful of studies have leveraged agent-based models (ABMs) to examine public health outcomes and policy interventions associated with uneven urban food environments. While providing keen insights about the role of ABMs in studying urban food environments, these studies underutilize real-world data on individual behavior in their models. This study provides a unique contribution to the ABM and food access literature by utilizing survey data to develop an empirically-rich spatially-explicit ABM of food access. This model is used to simulate and scrutinize individual travel behavior associated with accessing food in low-income neighborhoods experiencing disinvestment in Detroit (Michigan), U.S. In particular, the relationship between trip frequencies, mode of travel, store choice, and distances traveled among individuals grouped into strata based on selected sociodemographic characteristics, including household income and age, is examined. Results reveal a diversified picture of not only how income and age shape food shopping travel but also the different thresholds of tolerance for non-motorized travel to stores. Younger and poorer population subgroups have a higher propensity to utilize non-motorized travel for shopping than older and wealthier subgroups. While all groups tend to travel considerable distances outside their immediate local food environment, different sociodemographic groups maintain unique spatial patterns of grocery-shopping behavior throughout the city and the suburbs. Overall, these results challenge foundational tenets in urban planning and design, regarding the specific characteristics necessary in the built environment to facilitate accessibility to urban amenities, such as grocery stores. In neighborhoods experiencing disinvestment, sociodemographic conditions play a more important role than the built environment in shaping food accessibility and ultimately travel behavior.

Much of the literature examining associations between local food environments and obesity fail to consider whether or not respondents actually utilise the food stores around them. Drawing on survey data, this study examines the relationships between the neighbourhood food environment, mobility and obesity among residents from the lower eastside neighbourhoods of Detroit, Michigan. Certain dimensions of the local food environment are found to contribute to obesity, but these dimensions occur at different scales. Residents who rely on their immediate neighbourhood food environment have a higher likelihood of being obese than residents who do not utilise the stores around them. At a broader level, lower eastside Detroit residents with a greater concentration of fast food establishments around them have a higher possibility of being obese than residents with fewer fast food restaurants around them. The salience of the fast food environment warrants additional attention in terms of public health interventions.

This article explores Houston's two Chinatowns within the context of the city's recent urban reinvestment and revitalization initiatives. It provides a history of the Chinatowns and examines their changing condition during the years that Houston was promoting ethnic diversity and urban revival. The analysis is framed within the growth machine perspective, as initially explored in Houston by Joe Feagin, and later by Jan Lin and Igor Vojnovic. Houston's late-20th-century urban redevelopment initiatives occurred during a period in history when Houston's Chinese entrepreneurs lost their influence over the local growth machine. The eventual outcome was the erasure of Houston's downtown Chinatown and the displacement of its residents from their lucrative urban core location. The disappearance of Old Chinatown and other urban ethnic neighborhoods—including Little Saigon and Freedmen's Town—from the urban core all took place as the Houston media and public were celebrating diversity, pluralism, and ethnicity in the city.