The study looked at how different regions in the United States affect city prices. They found that prices are more stable when cities are in the same region. However, prices vary more if both cities are in the West, and less if they are in the Northeast. Prices also vary more if at least one city is in the South or West. Prices tend to converge if both cities are in the South, but not if one is in the West. Distance increases price differences and reduces convergence, especially if one city is in the South.