How Many Hispanics? Comparing Census Counts and Census Estimates

I. Overview

The number of Hispanics counted in the 2010 Census was nearly 1 million more than expected, based on the most recent Census Bureau population estimates, according to an analysis by the Pew Hispanic Center, a project of the Pew Research Center.

The 2010 Census count of Hispanics was 50,478,000¹, compared with 49,522,000 Hispanics in the bureau’s own estimates. The count was 1.9% higher (955,000 people) than the estimated population. In 32 states, the 2010 Census count of Hispanics was at least 2% higher than the estimates; in nine states, it was at least 2% lower than the estimates. In the nine remaining states and the District of Columbia, the difference was less than 2% in either direction.

By comparison, for the total U.S. population, the 2010 Census count of 308.7 million was barely lower (about 232,000 people) than the bureau’s population estimate for April 1, 2010. Compared with results a decade ago, the national Hispanic count in the 2010 Census was closer to bureau estimates than it was in 2000. The 2000 Census count included 10% more Hispanics than the population estimates, and state-level discrepancies also were larger than in 2010.

Unlike the decennial Census, designed to be a 100% count of the U.S. population, the Census Bureau’s population estimates are annual updates of counts from the previous census based largely on birth certificates, death certificates, immigration data and other government records.² The most recent published state population estimates for Hispanics were as of July 1, 2009. For this analysis, the Hispanic estimates were updated to Census Day, April 1, 2010, by extrapolating the 2009 estimates based on each state’s Hispanic population growth rate from 2008 to 2009. This report replaces an analysis published March 15, 2011, which examined Census 2010 data and population estimates from 33 states.

State Detail

The Pew Hispanic Center analysis indicates that states with large percentage differences between their Hispanic census counts and census estimates also were likely to have large percentage differences between census counts and census estimates for their total populations. This reflects the large role that Hispanics play in overall population growth—nationally, Hispanics accounted for 56% of the U.S. increase. Hispanics have accounted for most of the discrepancy between 2010 Census counts and census estimates of states’ total populations.

In addition, according to the Pew Hispanic Center analysis, states that have Hispanic populations under a million people (including many where Hispanic counts grew sharply) collectively had a larger percentage gap between their census counts and census estimates than did the nine states with larger, long-duration Hispanic communities.

Those nine traditional Hispanic states include Arizona, California, Colorado, Florida, Illinois, New Jersey, New Mexico, New York, and Texas. Each has more than a million Hispanic residents (except New Mexico, with 953,000). Collectively, 28% of their population is Hispanic. As a group, those states are home to 38.6 million Hispanics, according to the 2010 Census, and their aggregate census count was about 362,000 (or .9%) larger than their aggregate census estimate.

In the other 41 states and District of Columbia, Hispanics make up 7% of the total population. These states as a group are home to 11.9 million Hispanics, and their combined 2010 Census count was 593,000 people (or 5.3%) higher than their combined census estimate. Among them was Alabama, where the Hispanic census count of 186,000 people was 16% higher than its census estimate, the largest gap among states. At the other extreme, the census count of 39,000 Hispanics in Alaska was 14% below the most recent census estimate. (Smaller populations by nature tend to be more volatile than large ones, so even a small numerical difference could result in a large percentage change.)

In the nine states with large Hispanic populations, five had gaps of more than two percentage points in either direction between census estimates and census counts. In four, the count was higher than the estimate. In New Jersey, the census count of 1.555 million was 4.6% higher than the census estimate for Hispanics. In Florida, the census count of 4.224 million was 3.7% higher than the estimate. In New York, the census count of 3.417 million Hispanics was 2.9% higher than the census estimate. In New Mexico, the census count of 953,000 was 2.6% higher than the estimate of Hispanics.

In the nine states with large Hispanic populations, five had gaps of more than two percentage points in either direction between census estimates and census counts. In four, the count was higher than the estimate. In New Jersey, the census count of 1.555 million was 4.6% higher than the census estimate for Hispanics. In Florida, the census count of 4.224 million was 3.7% higher than the estimate. In New York, the census count of 3.417 million Hispanics was 2.9% higher than the census estimate. In New Mexico, the census count of 953,000 was 2.6% higher than the estimate of Hispanics.

As the accompanying table shows, there were differences between census counts and census estimates for Hispanics in most parts of the country.

Accuracy of Estimates

The accuracy of these census population estimates is important not only because they are the major source of basic demographic data in the years between census counts, but also because they are the basis for distributing billions of dollars in federal funds during those years. They are relied on for sample design and weighting in widely used federal surveys, including the bureau’s own American Community Survey and the Current Population Survey from which federal unemployment and poverty rates are calculated. The estimates also are used to calculate birth and death rates for the total population and for sub-populations such as race and ethnic groups.

The Census Bureau has invested study and effort over the past decade to improve its population estimates after the publication of 2000 Census counts pointed to a shortfall in census estimates published in the 1990s.

In 2000, the population estimate for April 1, 2000 of 274.5 million was about 7 million people short of the census count for that day of 281.4 million people, or 2.5%. Later analysis attributed much of the gap to a low census estimate of Hispanics, the nation’s largest minority group. The 2000 Census count of Hispanics of 35.3 million was nearly 10% larger than the official estimate for April 1, 2000 of 32.2 million.

Much of the problem, the bureau concluded, was that the estimates failed to account for growth in the number of unauthorized immigrants. Analysts also concluded the 1990 Census count had been too low, so the estimates began from a base that was too small.

At the state level, the gap between 2000 Census counts and census estimates of Hispanics was even wider (for this analysis the 1999 estimates were extrapolated to Census Day 2000). In eight states, the count was 50% or more above the estimate, higher than any variation found in the 2010 state census counts. In only three states was the census count within 2% of the census estimate.

The bureau made several changes to its population estimates methodology over the past decade. Most notably, it began including state-level data obtained from the American Community Survey, which collects information on characteristics of the U.S. population, including immigrants. The bureau also devoted additional effort to outreach in the 2010 Census to groups that have been hard to count in the past, such as immigrants.