While still a nascent operation, the Pensioner Party’s message resonates broadly with voters in Germany and across Europe. With a higher birthrate and greater immigration, the United States faces a less acute problem with government pension benefits, despite periodic flare-ups over Social Security and fears about the long-term fiscal stability of the pension systems for many state and local government workers.

Image Changes in public pension rules have caused outcries in Europe, including a demonstration in May on the streets of Marseille, France. Credit... Philippe Laurenson/Reuters

Most of the costs of an aging American society have to do with skyrocketing health care costs  far less of a problem in Europe. The widespread use of private pensions and employer-based savings plans in the United States also eases the pressure on taxpayers to pay retirement costs.

But in much of Europe, the need for change is more pressing.

State pension costs as a percentage of gross domestic product are edging steadily upward. In France, for example, they will reach 14.8 percent in 2050, from 13.3 percent today, according to the European Commission. That would put French pension costs on the high end of the European average. It would also be more than three times the portion of the United States economy devoted to federal retirement programs.

A measure introduced in 2003 by François Fillon, then the French employment minister, now prime minister, required public sector workers to serve 40 years before getting a full pension. But the rule was riddled with exemptions for train operators, electricity and natural gas workers, and other groups.

Most of those loopholes were closed last fall after those affected were promised higher pay to end a nine-day strike. Now Nicolas Sarkozy, the French president, wants to extend the required working time to 41 years by 2012 for the entire French work force, though without raising the formal retirement age from 60, as employers have demanded.

Opinion polls show that a majority of French people back the 41-year rule, but are opposed to increasing the retirement age.

Germany has gone further than France, probably because it is under more intense demographic pressure.