By Caren Bohan
WASHINGTON, May 8 (Reuters) - A Senate bill to overhaul U.S. immigration laws would help ease financial strains on the Social Security retirement program, government actuaries said on Wednesday in an estimate that marked the latest salvo in a debate over the legislation's impact.
In a letter to Florida Republican Senator Marco Rubio, who is one of the authors of the bill, actuaries for the Social Security Administration said the overall effect of the bill on the Social Security's finances "will be positive."
The analysis said the bill would create a net 3.22 million jobs over the next decade and boost U.S. gross domestic product by 1.63 percentage points over that period.
The letter came days after a hotly debated report from the Heritage Foundation, a conservative think tank, said the pathway to citizenship in the bill for undocumented immigrants could cost taxpayers trillions of dollars.
The sweeping immigration bill would boost funding for border security, revamp visa programs to allow for more high- and low-skilled workers and chart a 13-year path to citizenship for many of the 11 million illegal immigrants in the country.
The Heritage Foundation study, which was criticized by liberal supporters of immigration reform as well as some conservatives, said that over a lifetime, immigrants would end up costing the government because they would take in more in benefits than they would pay in taxes.
The think tank put the cost of the change in the law at $6.3 trillion over 50 years.
Critics of the study said it did not take into account how immigration reform could increase economic growth by making labor markets more efficient and companies more competitive.
Advocates for immigration reform contend that it would help ease pressure on government programs such as Social Security because it would result in a greater number of younger workers to support aging baby boomers, who are beginning to retire in large numbers.
The analysis from the Social Security actuaries could lend support to that argument.
It comes as the Senate Judiciary Committee is preparing this week to consider a raft of amendments to the bill.
The latest report from the Social Security Board of Trustees, issued in April 2012, estimated that the program's accumulated "trust funds" would be exhausted by 2033, meaning policymakers might need to raise taxes or cut benefits or both to deal with the shortfall.