“…Further, studies that focus exclusively on metropolitan areas or cities may suffer from sample selection bias. To remedy this, Hammond and Thompson (2006), Hammond (2006), Hammond (2004), Henry, Barkley, and Li (2004), Huang, Orazem, and Wohlgemuth (2002), Rupasingha, Goetz, and Freshwater (2002), Beeson, DeJong, and Troesken (2001), Nissan and Carter (1999), and Carlino and Mills (1987) investigated convergence and growth issues us-1 In 1969, the commuting zone region with the highest per capita personal income was Nantucket County, Massachusetts ($5,111). The commuting zone region with the lowest income was Maverick County, Texas ($1,349).…”