Louisville Kentucky - a city generally associated with the Kentucky Derby - also hosts the largest concentration of nursing-home and extended-care companies in the nation.
The long-term-care industry has helped spark a turnaround in the city and is a result of industry clustering. , to one of the buzz phrases in urban economic development: clustering. Humana has its headquarters in Louisville and as its influence grew, the health-insurance giant created spinoffs and attracted like-minded businesses. More here