This is a big month for census data releases. On September 10, the U.S. Census Bureau will release poverty statistics based on the Current Population Survey (CPS). On September 26, there is a different poverty-related release based on the American Community Survey (ACS).

At Arkansas Advocates for Children and families, we primarily rely on the ACS data when making year-to-year comparisons and when comparing Arkansas to other states.

Here’s why:

The CPS is an annual survey of about 100,000 households nationwide. Because of this relatively small sample size, year-over-year data at the state level have large margins of error. CPS data is often useful for looking at changes in poverty levels at the national level. But when looking at state data, the Census Bureau advises averaging two years of CPS data to make reliable comparisons of one state over time. They advise using three years of survey data to make comparisons between states.

One noteworthy point we do anticipate being in the CPS data is an increase in the number of people going without health insurance. This trend is especially troubling regarding rising rates of children without health insurance. To be clear, the trend we expect to see continue in tomorrow’s data does not suggest that fewer children are on government-sponsored health insurance programs alone, but that more children are without health insurance of any kind.

The ACS surveys 3 million households annually – 30 times as many as the CPS. The households surveyed include “group quarters,” such as nursing homes, military barracks, college dormitories, and prisons. Because of the large sample sizes and the fact that more of the population is included, the ACS is often preferred for making state and local estimates or for making comparisons between the states. The ACS also includes information on housing costs, commuting information, and health insurance data that is not included in the CPS.

While both data sets are useful for different reasons, as a state policy organization, AACF places a greater emphasis on the ACS, especially for making year-over-year comparisons or for making comparisons between states.

Stay tuned here on the blog for our analysis of the data as it comes out throughout the month.