This means that our county total population projections will be consistent with the latest state projections available from the federal government. These projections, along with historical data, can be seen in figure 3 . The simplest approach assumes that counties will continue to hold constant shares of the state's population over the length of the projection period. For instance, assume that each county will hold its 1997 share of the state's population during the period from 2000-2020. That is, all counties grow at the same rate.
Alternative strategies involve assumptions about patterns of changing shares.
Thus, counties are allocated increasing or decreasing shares of the state's projected population. We developed two county projections based on assumptions that each county's share of the state's population change after 1997 would be the same as its share of the state's change between 1990 and 1997, or between 1996 and 1997. Some observations about these strategies are worth mentioning. The constant 1997 share strategy results in population growth for all 92 counties, since the state's population grows during the projection period. Using the share of change between 1990 and 1997 is reasonable for many counties, but produces unreasonable results for counties that experienced changing trends in recent years.