LI's population inching upward, census shows

The 2010 census, a survey of all households in the nation that is considered the most accurate population count available, recorded 1,339,352 residents in Nassau County on April 1, 2010. By July 1, 2010, the bureau estimated the county's population rose to 1,341,033. By July 1, 2011, the population grew to an estimated 1,344,436.

The Census Bureau's population estimates are the first released since the 2010 census.

The bureau uses a "components of change method" to calculate population. That includes records on births and deaths plus other data to calculate net international migration and domestic migration.

Though pleased to see population growth reflected in the estimates, Seth Forman, a demographer and public policy professor at Stony Brook University, said he was concerned about the figures from the bureau's domestic migration estimates. The agency's 2010 and 2011 figures for Long Island showed fewer residents moved to other areas of the country than in earlier years. In 2008, the bureau reported domestic migration losses for Long Island at more than 16,000, compared with about 5,500 in 2011, he said. He added that population estimates for the region came in higher than the 2010 census count.

Forman said IRS tax return data for filers and their dependents, as well as Medicare enrollment records for people 65 and over, are used to calculate domestic migration patterns but did not capture all households.

However, Alexa Jones-Puthoff, chief of the population estimates branch of the Census Bureau, said the federal tax return information was a "relatively complete data set" that covered about 80 percent of the population at the state level.

The bureau's calculations don't use the tax return data to directly estimate the number of domestic migrants, in any case, she said. Instead they use the data to calculate a rate that is then factored into a population estimate.

His cautions notwithstanding, Forman said: "I would say it's not a terribly harmful misestimate, if that's what it is. I want to make clear I don't have any more accurate estimate than they do. So, I don't think it's harmful to the region. If anything, I think it's helpful showing the population growing."