Per Capita Income (PCI) is one of the most widely used indicators for gauging the economic performance and changing fortunes of local economies. It is used as a yardstick to assess the economic well being of a region's residents and the quality of consumer markets. It serves as a barometer for calibrating the economic performance of a region over time and to judge differences in relative economic prosperity between regions. Shifting trends in local per capita income growth have important social and political ramifications and significant implications in formulating local economic development strategies and initiatives.

Personal income is measured as a flow throughout the year, while the measurement of population is at one point in mid-year. Therefore, per capita income is distorted if a significant change in population occurs during the year.

For smaller counties in particular, per capita income in any given year may be exceptionally high or low for the short run because of unusual local conditions, such as a bumper crop, a catastrophe, or a major construction project as the building of a dam or nuclear power plant.

Farm incomes are notorious for being especially volatile year-to-year, owing to changing weather, commodity market conditions, and alterations in government programs. Therefore, the per capita income of farm-dependent counties may exhibit sharp fluctuations over time.

The presence of large institutional populations--such as residents attending a local college or the residents of a local prison or state mental institution--can significantly lower the per capita income estimates of an area. Such results may not reflect the relative economic well being of the non-institutional population and may mislead if care is not given to their interpretation.

Figure 1 depicts Jefferson County's annual per capita personal income over 1970-2022 in current and constant (2017) dollars. Constant dollar measurements remove the effects of inflation. They allow for comparison of changes in the real purchasing power of Jefferson County over time.

When measured in current dollars, Jefferson County's per capita personal income increased 1,522.91%, from $3,876 in 1970 to $62,898 in 2022. When measured in constant 2017 dollars to adjust for inflation, it advanced 176.44%, from $19,608 in 1970 to $54,203 in 2022.

Figure 2 traces Jefferson County's and Washington's annual real per capita personal income for the period 1969-2022 to illustrate real per capita personal income patterns over time. During this 54-year period, Jefferson County's real per capita personal income rose from $19,819 in 1969 to $54,203 in 2022, for a net gain of $34,384, or 173.49%. In comparison, Washington's real per capita personal income advanced from $22,551 in 1969 to $64,917 in 2022, for a net gain of $42,366, or 187.86%.

Figure 3 shows the short-run pattern of Jefferson County's real per capita personal income growth by tracking the year-to-year percent change over 1970-2022. The average annual percent change for the entire 53-year period is also illustrated on this chart to provide a benchmark for gauging periods of relative high--and relative low--growth against the backdrop of the long-term average.

On average, Jefferson County's real per capita personal income grew at an annual rate of 1.96% over 1970-2022. The county posted its highest growth in 1983 (6.77%) and recorded its lowest growth in 2009 (-5.45%). In 2022, Jefferson County's real per capita personal income declined by -3.92%

Over the past five decades some counties have experienced extreme swings in growth, and often such swings have tended to coincide with the decades themselves. Figure 4 again traces the annual percent change in Jefferson County's real per capita personal income since 1970, but this time they are displayed with average growth rates for the decade of the 1970s, 1980s, 1990s, 2000s, 2010s, and 2020-2022.

During the 1970s, Jefferson County's annual real per capita personal income growth rate averaged 2.75%. It averaged 1.52% in the 1980s, 2.56% in the 1990s, 0.96% during the 2000s, 2.13% during the 2010s, 1.59% thus far this decade (2020-2022).

Figure 5 compares the decade average growth rates for Jefferson County noted in the previous graph with the corresponding decade averages for Washington and the nation. As the chart reveals, Jefferson County's average annual real per capita personal income growth outperformed Washington's average throughout the 1970s (2.75% vs. 2.53%), surpassed Washington's average during the 1980s (1.52% vs. 1.41%), recorded under Washington's average throughout the 1990s (2.56% vs. 2.58%), outgained Washington's average throughout the 2000s (0.96% vs. 0.96%), amounted to less than Washington's average throughout the 2010s (2.13% vs. 2.73%), and trailed Washington's average over the 3 year period of the current decade, 2020-2022 (1.59% vs. 2.07%).

Finally, relative to nationwide real per capita personal income growth trends, Jefferson County outperformed the nation throughout the 1970s (2.75% vs. 2.37%), posted below the nation during the 1980s (1.52% vs. 2.19%), exceeded the nation in the 1990s (2.56% vs. 2.01%), fell under the nation over the 2000s (0.96% vs. 1.10%), topped the nation during the 2010s (2.13% vs. 1.97%), and trailed the nation over 2020-2022 (1.59% vs. 1.78%).