According to the Oregon Employment Department, real average annual earnings and per-capita income both grew more than three percent between 1997 and 1999. The Census Bureau's monthly and annual surveys found solid median income and wage gains, as well. These and other sources of wage and income data find real gains in the late 1990s. The Progress Board's estimate of income is less precise than other studies'. As a result, the Board must predict which category is most likely to contain the median and then estimate where the median falls within that category.
All surveys provide estimates.
The OPS, in this instance, provides estimates of estimates. The Board's median income calculation is also influenced by the measure of inflation it chose to apply. If the US consumer price index is used, median income seems to grow between 1997 and 1999. If the Portland-area index is applied, income seems to fall. It is not clear which is best for Oregon, but findings so sensitive to the inflation measure should be treated cautiously.