Among the Reasons Why a Complete Census Count is Important...

In an era when the US Congress is hacking away at budgets, including that of the Census Bureau, it is good to be reminded of the many ways in which the complete count is critical to our understanding of demographic trends. The Pew Research Center today issued a report showing that the intercensal estimates of the Hispanic population tended to be considerably different from the census count in those states, such as in the Southeast, where the Hispanic population is still relatively small, but is rapidly growing. As Jeff Passel and D'Vera Cohn note:

The six traditional Hispanic states for which Hispanic counts from the 2010 Census have been released include Arizona, California, Colorado, Illinois, New Jersey and Texas. Each has more than a million Hispanic residents and collectively, 31% of their population is Hispanic. As a group, those states house 30 million Hispanics, according to the 2010 Census, yet their aggregate census count was only 88,000 (or .3%) larger than their aggregate census estimate. 

In the other 27 states, Hispanics make up 7% of the total population. These states as a group house 8.7 million Hispanics, and their combined 2010 Census count was 501,000 people (or 6.1%) higher than their combined census estimate. Among them are Alabama, where the Hispanic census count of 186,000 people was 16% higher than its census estimate, the largest gap among states seen so far.

Perhaps most troubling, however, is that in Arizona the census count was lower than the census estimate for the Hispanic population. 

The gap in Arizona was almost entirely due to a lower-than-expected Census count in Maricopa County, which includes Phoenix.

It seems likely, of course, that the harsh laws recently passed against undocumented immigrants have had an impact on the overall growth of the Hispanic population.