Measuring spatial mismatch and job access inequity based on transit-based job accessibility for poor job seekers

The few spatial mismatch studies that have examined spatial mismatch based on job accessibility consider travel time as the sole travel impedance. However, travel cost (e.g., fuel cost, parking fee and transit fare) is also an important factor in determining job accessibility especially for poor job seekers and needs to be integrated into job accessibility measure, because socially vulnerable people including poor job seekers could be disadvantaged by high travel cost (e.g., poor job seekers discouraged from using transit services for commuting due to high fare). By focusing on transit-based job accessibility, this study seeks to improve the assessment of spatial mismatch based on job accessibility by taking transit fare into account and determine the inequity in job accessibility for poor job seekers by conducting comparisons across areas and races. Based on a study of the Chicago Metropolitan Area, we first determine the demand for each census tract's jobs based on a gravity model that integrates both transit-based travel time and transit fare of poor job seekers from other census tracts. Then, we measure the job accessibility for each census tract based on a gravity model considering the attraction of low-pay jobs weighted by job demand and the friction of transit-based travel time and transit fare. Finally, we assess spatial mismatch by comparing the job accessibility of central city poor job seekers against their suburban counterparts and determine the job access inequity for poor job seekers by comparing the results before and after including transit fare across different areas and races. The results show that central city poor job seekers, either before or after including transit fare, do not suffer from spatial mismatch and tend to have higher job accessibility compared to their suburban counterparts. However, the results obtained from including transit fare are quite different from those that considered travel time only, especially with respect to the differences between poor job seekers of different races living in different areas. For policymakers to be fully informed about spatial mismatch, it is important to take both travel time and transit fare into account.