Abstract
Washington State Government forecasts future population of each county as one of the implement process of growth management policy. Over 70% of forecasted figure are evaluated as "good" or "fair" based on population change for the last 40 years. Each county sets its future population within the range of forecasted future population and allocates future population among municipalities. Allocation policy and method are left on hands of counties. Forecasting process is scientific, while allocation one is political. These practices have been well conducted mainly due to more emphasis on quality of life than population size among municipalities, good relationship among state, county, and city/town, flexibility of the forecasting process, petition system, and high credibility of the state population forecasting agency, although there are some issues such as risk to accommodate unstopped growth and insufficient analysis of developable land
