• by Joe Mandese  @mp_joemandese, May 3, 2012

Nielsen this morning released preliminary estimates for television’s so-called “universe” -- the percentage of U.S. households with at least one conventional TV set capable of receiving at least one conventional TV signal -- and for the second year in a row, it has declined, albeit at a miniscule rate. Like last year’s decline, Nielsen executives attribute some of the reduction to changes in the U.S. Census’s estimates for the number and composition of U.S. households, which the TV universe estimates are based on, but they say at least part of it is a function of changes in the media technology composition of U.S. homes. Precisely how much, they cannot say.

“We continue to see increased media use proliferation, fueled by consumers able to watch professional, long-form video delivered traditionally and over the Internet by a number of devices, such as game consoles, computers, smartphones, tablets and over-the-top streaming like Apple TV,” explains Pat McDonough, senior vice president of insights and analysis at Nielsen, adding that Nielsen estimates that TV penetration, “as currently defined,” will be at 95.8% of U.S. households in January 2013.

The preliminary estimates, which will be used as the basis of all of Nielsen’s calculations –- and the planning, buying, posting and guarantees for TV advertisers next year –- project the number of TV households will decline to 114.1 million for 2013, from 114.7 million in 2012.

The number of persons 2+ living in those TV households will decline to 289.2 million in 2013 from 289.3 million in 2012.

The final 2013 TV household and persons universe estimates will be released in August.

McDonough explains the impact of the 2010 U.S. Census data releases, noting that they occur over two years: “The 2012 universe estimates were the first to reflect the 2010 Census results for total population, total households, and ethnic population totals.

“These advance 2013 universe estimates are the first to reflect the 2010 Census results for demographic details (persons by age, sex, and ethnicity) as well as ethnic households.”