By Michael P. Norton

State House News Service

BOSTON -- The population of Massachusetts, a factor for everything from business growth and property taxes to congressional representation, is expected to grow 4.4 percent between 2010 and 2030, according to a study released Wednesday.

The UMass Donahue Institute's Population Estimates Program study concluded the Massachusetts population will increase by 290,589 over the 20-year period, estimating a 2030 population of 6,838,254. Most the growth, or 3.2 percent, is expected to occur between 2010 and 2020.

By comparison, the population of Massachusetts grew by 3.1 percent between 2000 and 2010, a period when the U.S. population increased by 9.7 percent.

With other states growing faster than Massachusetts, the Bay State lost one of its seats in the U.S. House following the 1990 Census and another after the 2010 Census. Massachusetts holds nine seats in the U.S. House of Representatives after the state Legislature put in place new district boundaries for the 2012 election cycle.

If the population estimates in the study hold up, Massachusetts may be at risk of losing another seat following decennial U.S. Census counts scheduled for 2020 and 2030.

While the state's 4.4 percent growth rate over the 20-year period is more than the 3.3 percent growth rate for the Northeast as a whole, the study predicts the U.S. population will grow 15.6 percent over the same 20-year period, rising 8.2 percent between 2010 and 2020 and another 7.4 percent between 2020 and 2030.

Under the estimates released Wednesday, Massachusetts' population will increase an average of only 0.22 percent a year between 2010 and 2030.

The study projects an increase in the state's population of individuals 65 and older. That group accounted for 14 percent of the population in 2010, but is expected to represent 21 percent by 2030. Conversely, individuals 19 years old or younger accounted for 25 percent of the population in 2010, a share expected to fall to 22 percent by 2030.