Resumen
Urban spatial structure evolution, when using employment as the proxy, can be explained by the change of employment distribution. In this study, we measure the 361 US metro areas (metros) by employment shares, in five submetro sections (i.e., main-center, sub-centers, non-center clusters, non-cluster urban areas, and rural areas), and explore the spatial patterns of submetro growths. We use recognized methods to delimit urban and rural areas, identify employment centers with relative thresholds, and categorize the metros into three (i.e., small, midsize, and large) categories. Then we use descriptive statistics to determine the dynamics of employment growth in the five submetro sections. The results suggest that metros? spatial structures and growth patterns vary greatly across different size categories. We found that (1) small metros tend to have growth in the main-center or non-cluster urban areas; (2) midsize metros may be in the critical period of forming sub-centers, which also may be an effective way to curb urban expansion into rural areas; and, (3) the five submetro growths in large metros tend to be positively associated with one another, except for the main-center.