For the purposes of this credit, the counties in Mississippi are classified as Tier Three (less developed), Tier Two (moderately developed), and Tier One (developed). The counties are evaluated and ranked each year based on the unemployment rate and per capita income of each county for the most recent 36 month period. They are then divided into the three previously mentioned groups with one-third of the counties in each group. The classification for a specific county can change from year to year based on this evaluation.
35 Miss. Code. R. 10-01-104