Italy is contending with a public debt, built up under a succession of Christian Democratic governments, that helped the country emerge from dire poverty after World War II to become Europe’s third-largest industrial economy.

Especially in the poorer Italian south, the Christian Democrats put millions of people on the state payroll in a jobs-for-votes system that many say has persisted under Prime Minister Silvio Berlusconi. The quid pro quo worked so long as the economy was expanding, but now is seen as one of the major threats to Italy’s solvency.

In 2009, the most recent year for which data is available, an estimated 3.5 million Italians were on the state payroll out of a work force of 23 million, according to the Ministry for the Public Administration and Innovation. On Mr. Berlusconi’s watch, government expenditures — including the cost of public administration and defense — rose to more than $1 trillion in 2010 from $753 billion in 2000.

Image Especially in the poorer Italian south, many say a jobs-for-votes system has persisted. Credit... The New York Times

Analysts attribute some of the rise to the introduction of the euro in 2001 and the rising cost of pension spending in a nation that will soon have more retirees than workers, as well as to soaring health care costs.

But they say it also stems from deals Mr. Berlusconi has made with powerful politicians from both the north and the south to get the votes needed to hold together his government. Those votes mean the government is loath to stop the flow of money. Even with the new austerity measures, “They haven’t closed the taps,” Mr. Micossi said. Some say the jobs-for-votes mentality derives from Italy’s feudal heritage. Italy was a patchwork of warring fiefs before unification 150 years ago, and personal networks are often still seen as more powerful than institutions.

Even today, the concept is: “I understand the state if it gives a benefit to my person, family, business,” said Luigi Musella, a historian at the University of Naples and the author of “Clientelism,” about Italy’s quid pro quo politics.