When is it best to use American Community Survey (ACS) 1-year, 3-year, or 5-year estimates?
You must think about the balance between currency and sample size/reliability/precision. The 1-year and 3-year estimates are more current than the 5-year estimates. However, the 5-year estimates have a larger sample size and are therefore usually more precise than the 1-year or 3-year estimates. The increased precision of a 5-year estimate may be particularly important if you are studying a small area or a small population subgroup.
For more detailed information, visit When to use 1-year, 3-year, or 5-year estimates on the American Community Survey (ACS) website.