Preparing for the encore years

During a scene in "The Sopranos," the popular TV series on the Mafia, a reluctant gangster tells his mob boss Tony Soprano that he has inherited $2 million and he and his wife are thinking of retiring and moving south to Florida.

"What're you, a hockey player?" Tony jokes. He reminds his friend that he took an oath and that retiring from their line of work is not an option. It turns out the gangster was also an informant for the F.B.I., and ends up killing himself in despair.

Fortunately, most of us have better retirement options. But the social security systems that many depend on to help them live comfortably later in life are facing the stark reality of an aging population, particularly in Japan and Western Europe, where the number of workers supporting retirees will drop precipitously in the coming decades.