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Wednesday, April 13, 2011

I hate to brag, but…

Sometimes a little bragging is in order. This is one of those times.

Every year, COMPASS staff develop population estimates for Ada and Canyon Counties and cities, with input from the COMPASS Demographic Advisory Committee (DAC). Those estimates are based on the most recent Census data, plus a variety of other factors, including household vacancy rates, average household size, and other information.

There are a variety of sources of these data, and sometimes those sources do not agree. COMPASS staff and DAC members carefully consider the different data sets and choose which to use to estimate the area’s population.

Census data are collected every 10 years. In the first years following data collection, the Census data are likely still fairly accurate. However, as years pass and we get further from a Census year, the data are less accurate. What that means is it gets harder and harder to develop an accurate population estimate as we get further away from the most recent Census year. Year 10 (2010 in this case) is always the hardest.

In fact, knowing how difficult it is to develop an accurate estimate in Year 10, the COMPASS Board chose not to adopt the COMPASS staff recommended estimates for 2010 and to wait for Census numbers to be released instead.

Census numbers for 2010 were released last month. How did those COMPASS recommended estimates for 2010 compare to the actual Census numbers?

This is where the bragging comes in.

Overall, COMPASS estimates were off (high) by 0.9% for Ada and Canyon Counties combined. For Ada County, COMPASS over-estimated by 1.4%; for Canyon County, COMPASS under- estimated by a mere 0.1%.

These numbers are impressive by any standards. Given the fact that the baseline Census data were 10 years old and considering the rollercoaster decade that was the 2000s, they are downright phenomenal.

Congratulations to Carl Miller, COMPASS Principal Planner for Demographics, and the entire COMPASS Demographic Advisory Committee. Your efforts, and results, are to be commended.

(Want to see the numbers I'm talking about? Click here and navigate to page 28.)

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Community Planning Association of Southwest Idaho

COMPASS is the designated Metropolitan Planning Organization responsible for transportation planning in Ada and Canyon Counties. The COMPASS Board comprises 39 members representing the cities, counties, highway districts, educational institutions, state agencies, and other entities within the two counties. COMPASS plays an important role in making decisions about future long-range transportation needs in the Treasure Valley, taking into consideration environmental and economic factors that affect the quality of life.