“Census Bureau and a multitude of private sector research shows that sending a replacement questionnaire to households can significantly increase response rates in the end,” Census Bureau Director Robert Groves said. “We estimate that the second mailing could increase America's mail participation rate in the 2010 Census by 7 to 10 percentage points, and doing so would save taxpayers more than $500 million.”

According to the Census Bureau, every percentage point increase in the national participation rate by mail saves about $85 million. It costs the government just 42 cents in a postage paid envelope to get a questionnaire back in the mail, but it costs taxpayers an average of $57 to count a household that fails to mail it back.

Second questionnaires were mailed last week to every housing unit in areas that had a mail response rate of 59 percent or less in 2000, or about 24.7 million households. The questionnaires were sent to all households, regardless of whether they had already returned their 2010 Census form.

In areas that had response rates between 59 and 67 percent -- below the national average of 67 percent -- replacement forms will be sent only to households that have not yet mailed back their completed 2010 Census form. These 15 million households will receive a second form April 6-10.

Households have until mid-April to mail back their forms before census takers begin going door to door to residences that failed to respond.

“We understand that people lead busy lives and may not have gotten around to sending back their forms yet,” Groves said. “The replacement form gives them a second chance to get counted and help ensure that their community gets its fair share of political representation and federal funds over the next 10 years.”

Currently, the national mail participation rate is 60 percent, with some of the lowest rates in Alaska, California, Texas, New Mexico and Oklahoma. The latest national and local participation rates can be viewed athttp://2010.census.gov/2010census/take10map.

The 2010 Census is a count of everyone living in the United States and is mandated by the U.S. Constitution. Census data are used to apportion congressional seats to states, to distribute more than $400 billion in federal funds to tribal, state and local governments each year and to make decisions about what community services to provide. The 2010 Census form is one of the shortest in U.S. history, consisting of 10 questions, taking about 10 minutes to complete. Strict confidentiality laws protect the respondents and the information they provide.