In China, the 65-and-older population will rise from 11 percent of the working-age population in 2010 to 42 percent in 2050. In the United States, this old-age dependency ratio will rise from 20 percent to 35 percent.
In response, governments are raising retirement ages and slashing benefits. In 30 OECD countries, the average age at which men can collect full retirement benefits will rise to 64.6 in 2050, from 62.9 in 2010; for women, it will rise from 61.8 to 64.4. Italy is raising the age from 59 to 65.
In the wealthy countries it studied, the OECD found that the pension reforms of the 2000s will cut retirement benefits by an average 20 percent.
Even France, where government pensions have long been generous, has begun modest reforms to reduce costs. France has raised the number of years people must work before they can receive a full pension from 41.5 to 43. More changes are likely coming.
"France is a retirees' paradise now," says Richard Jackson, senior fellow at the Center for Strategic and International Studies. "You're not going to want to retire there in 20 to 25 years."
The fate of government pensions is important because they are the cornerstone of retirement income. Across the 34-country OECD, governments provide 59 percent of retiree income, on average. The government's share ranges as high as 86 percent in Hungary. In the United States, the world's largest economy, it's about 38 percent.
If rich countries don't cut pension costs even more, says Standard & Poor's, a credit-rating agency, their government debt will more than triple as a percentage of annual economic output by 2050. The debt of most countries would drop to what is commonly called junk status.
Many of those facing a financial squeeze in retirement can look to themselves for part of the blame. They spent many years before the Great Recession borrowing and spending instead of setting money aside for old age. In the U.S., households took on an additional $5.4 trillion in debt - an increase of 75 percent - from the start of 2003 until mid-2008, according to the Federal Reserve Bank of New York. The savings rate fell from nearly 13 percent of after-tax income in the early 1980s to 2 percent in 2005.
The National Institute on Retirement Security estimates that Americans are at least $6.8 trillion short of what they need to have saved for a comfortable retirement. For those 55 to 64, the shortfall comes to $113,000 per household.
"People are going to be shocked at how little they have," says Alicia Munnell, director of Boston College's Center for Retirement Research. "For some middle-income people, it will mean canceling the RV" - the recreational vehicle that has become a symbol of retiree life in America. For those worse off, she says, it could mean an old age in poverty.
THE FINANCIAL CRISIS MAKES THINGS WORSE
As if demographics weren't burden enough, the outlook became worse when the global banking system went into a panic in 2008 and tipped the world into the worst recession since the 1930s.
Government budget deficits - the gap between what governments spend each year and what they collect in taxes - swelled in Europe and the United States. Tax revenue shrank, and governments pumped money into rescuing their banks and financing unemployment benefits and other welfare programs.
That escalated pressure on governments to reduce spending on pensions or raise revenue. Hungary took one of the most draconian steps: It demanded that its citizens surrender their private retirement accounts to the government or give up their government pensions. Poland seized a portion of private retirement accounts. Ireland imposed an annual tax on retirement accounts.
The Great Recession threw tens of millions of people out of work worldwide. For many who kept their jobs, pay has stagnated the past five years, even as living costs have risen, making it tougher to save for retirement. In addition, government retirement benefits are based on lifetime earnings, and they'll now be lower. The Urban Institute, a think tank in Washington, estimates that lost wages and pay raises will shrink the typical American worker's income at age 70 by 4 percent - an average of $2,300 a year.
Leslie Lynch, 52, of Glastonbury, Conn., had $30,000 in her 401(k) retirement account when she lost her $65,000-a-year job last year at an insurance company. She'd worked there 28 years. She has depleted her retirement savings trying to stay afloat.
"I don't believe that I will ever retire now," she says.
She also worries about her children, all in their 20s: "I don't think my three sons will ever retire" because pay raises have been so weak for so long.
Less money from a government pension isn't the only factor weighing on future retirees. When the financial crisis struck five years ago, the world's central banks cut interest rates to record lows to stop the economic free-fall. That also punished people with much of their money in investments that pay interest.
"The low-interest rate environment has been brutal," says Catherine Collinson, president of the Transamerica Center for Retirement Studies. She points out that $500,000 in savings would yield $25,000 a year at an interest rate of 5 percent, just $2,500 at 0.5 percent.
The crisis also frightened many away from the stock market. Stocks can be riskier than other investments, but they yield more long term. Many investors have shunned stocks while the world's stock markets have soared. In the United States, the Dow Jones industrial average has risen nearly 150 percent since March 2009. Japan's Nikkei index is up 56 percent just this year.
The past five years have been so tumultuous that some people have been reluctant to invest at all.
