COLUMBUS, Ohio - After nearly 40 years in public education, Patrick Godwin spends his retirement days running a horse farm east of Sacramento, Calif., with his daughter.

His departure from the workaday world is likely to be long and relatively free of financial concerns, after he retired last July at age 59 with a pension paying $174,308 a year for the rest of his life.

Such guaranteed pensions for relatively youthful government retirees - paid in similar fashion to millions nationwide - are contributing to nationwide friction with the public sector workers. They have access to attractive defined-benefit pensions and retiree health care coverage that most private sector workers no longer do.

Experts say eligible retirement ages have fallen over the past two decades for many reasons, including contract agreements between states and government labor unions that lowered retirement ages in lieu of raising pay.

With Americans increasingly likely to live well into their 80s, critics question whether paying lifetime pensions to retirees from age 55 or 60 is financially sustainable. An Associated Press survey earlier this year found the 50 states have a combined $690 billion in unfunded pension liabilities and $418 billion in retiree health care obligations.

Three-quarters of U.S. public retirement systems in 2008 offered some kind of early-retirement option paying partial benefits, according to a 2009 Wisconsin Legislative Council study. Most commonly, the minimum age for those programs was 55, but 15 percent allowed government workers to retire even earlier, the review found. The study is widely regarded as the most comprehensive assessment of the issue.

Police and firefighters often can retire starting even younger - at around age 50 - because of the physically demanding nature of some of those jobs.

Yet with cities, counties and states struggling to pay pension bills, changes are afoot.

In November, San Francisco voters supported a local ballot initiative to hike minimum retirement ages for some city workers. Since that time, laws increasing retirement ages for government workers were signed in Rhode Island and Massachusetts in efforts to address underfunded pension systems.

Earlier in New Jersey, part of a legislative deal struck between Democrats and Republicans raised the normal retirement age from 62 to 65.

An initiative circulating for California's 2012 state ballot seeks to increase the minimum retirement age to 65 for public employees and teachers, and to 58 for sworn public safety officers.

Godwin said all the antagonism toward public retirees is misplaced. His pension payout follows 36 years as an English teacher and school administrator in California, with two years' sick-leave credit added for never being absent.

He said lack of accountability on Wall Street and exorbitant corporate salaries are a more justified target of the public's anger.

"Those things I think are a much larger problem than what a public employee is making as a pension," he said. The AFL-CIO labor coalition's Executive PayWatch project estimates chief executives went from making 42 times the average blue collar worker's salary in 1980 to 343 times as much last year.

Overall, Americans are working to older ages - even with the expanded ability for some to collect partial pensions younger if they retire. Over the past 20 years, the average retirement age for men has edged up to 64, for women to 62, according to the Center for Retirement Research at Boston College.

Data compiled by the U.S. Bureau of Labor Statistics show 29 percent of people between 65 and 69 worked at least part-time last year, up from 24 percent a decade ago and 21 percent in 1994. Almost 7 percent of people 75 or older were employed in 2010, compared to less than 5 percent 15 years ago.

Experts say no reliable figures exist that could show whether public sector workers retire younger than their private-sector counterparts. That's because the Bureau of Labor Statistics has no way of defining "retirement," and nearly all analyses involving the American workforce begin with the bureau's data.

It is clear, though, that most private-sector workers no longer receive defined-benefit pensions that will pay them for life. Most must wait until age 65 or 67 to collect their full Social Security benefit or draw from 401(k) accounts that are invested in the stock market and, in many cases, have sustained significant losses during the recession.

It is this shift in the style of benefits, and not the age of retirement, that should be scrutinized, said Hank Kim, executive director of the Washington, D.C.-based National Conference on Public Employee Retirement Systems, which advocates for government pensions.

"I think the biggest difference between the private and the public sector is that, for whatever reason, the private sector has largely abandoned the pension system," he said.

Kim believes that shift has left a generation of private employees - who make up the bulk of the American labor force - unprepared for retirement. In 2010, there were 18 million government workers and 94 million private sector workers in the U.S.

Rising retirement ages and reduced pension payouts for many private-sector workers are emboldening those seeking to rein in the obligations of overextended public pension systems.

Former California state Assemblyman Roger Niello, a Republican, is backing the proposal to take the age issue to California voters next year.

"It's a huge concern, arguably maybe the biggest concern aside from things where the system is being abused, like pension-spiking," said Niello, referring to the practice of artificially inflating retirement benefits by boosting pay at the end of an employee's career.

Defenders say union-negotiated retirement packages help attract and keep people in jobs necessary to society, whether teaching, environmental protection, law enforcement or garbage collecting.

Maureen Reedy, a long-time elementary instructional specialist in Upper Arlington, Ohio, a Columbus suburb, said benefits form part of the financial equation workers use to decide whether to go into public service.

"After 20 years, most teachers are making $50,000 - woo-hoo," she said. "Our pension and our security are part of the long-range outlook of our profession."

Ohio, New Jersey and Wisconsin were among states this year that sought to limit the power of public employee unions, in part out of concern over rising pension costs. Reedy, 53, was considering retirement before Ohioans voted in November to repeal a new law making sweeping changes to the collective bargaining abilities of unions representing 350,000 public workers. Pension changes are still on the state's agenda.

Some states began raising retirement ages around five years ago, before the issue had garnered wide public attention. Illinois and Missouri, for example, increased the normal retirement age to 67. Before the change, Illinois workers could retire with full benefits at 60 after just eight years of service.

Matt Mayer, president of the Buckeye Institute for Public Policy Solutions, a conservative think tank in Ohio, believes states' pension woes could be remedied by having their public pension systems operate more like the federal Social Security system.

"Frankly, I don't have as much a concern about when they retire as I do about when they get access to the pension," he said. "I believe in the economic freedom of workers. If a teacher wants to retire at 55, fine. They just don't get their pension until 65."