Outmigration is one of the best known and least understood problems facing Michigan. The Detroit News utilized several sources to answer questions about who was leaving the state, their educational attainment, income levels and destinations.
Among the sources was the U.S. Census Bureau, which last year for the first time released demographic profiles of those people who had left the state.
The analysis also utilized records from the Internal Revenue Service, which tracks people by their tax returns to create a database of county-to-county moves.
To get at the big number -- how many people are leaving -- The News relied upon the Census Bureau's annual migration estimates that are based in part on the IRS information.