By Marion Lloyd, Globe Correspondent

 HAVANA - After decades of service as a government librarian and Communist Party militant,
 Caridad, a sparrow-thin widow, thought the least she deserved was a quiet retirement.

 She now works harder than ever, and in a profession once reviled as embodying the worst evils of
 pre-Revolutionary Cuba: domestic service.

 Unable to make ends meet on her government pension of about $3.60 a month, she took a job
 cleaning for and caring for an 87-year-old neighbor who receives valuable US dollars from a
 daughter in Mexico. The $10 a month Caridad earns for the work has made the difference between
 near-starvation by the government ration card and barely getting by.

 The return of the maids is seen by sociologists in Cuba and the United States as a sign that this
 country's once-vaunted equality among the classes is fast becoming a thing of the past.

 ''I never imagined I'd be cleaning houses, particularly at this age,'' said Caridad, 88, who gave only
 her first name for fear of government reprisals.

 Though thousands of Cubans have gone into domestic service over the past decade, the work is
 technically illegal since it does not fall within the handful of sectors in which Cubans are permitted to
 earn US dollars.

 But Caridad said police generally look the other way. ''They know we have no choice. In Cuba, if
 you don't have dollars, you don't have anything,'' she said, gesturing around her grim two-room
 tenement in Centro Havana, in the shell of what was once an elegant Spanish colonial mansion.
 ''Anyway, what are they going to do to me besides bury me?''

 Cuba's National Assembly voted earlier this month to amend the constitution to make the country's
 socialist system ''irrevocable'' to make sure that ''capitalism will never return again'' to this
 Caribbean island. But that hasn't stopped the growth of capitalist-style workers such as maids.

 Critics say the tolerance toward domestic service is largely owing to government officials' being the
 biggest employers.

 ''All the big officials have servants, only they don't call them that. They call them `domestic
 workers,''' said Caridad's neighbor, who makes a living renting pirated videos and who asked to
 remain anonymous. ''Still, it's capitalism all the same.''

 ''Dollarization'' allows Cubans to receive dollars from abroad and trade in them at home in
 designated stores.

 The dollarization reforms, implemented in 1991 after the collapse of the Soviet Union, had been
 Cuba's economic lifeline during the Cold War. The program has created a new economic apartheid
 between those who earn dollars, the preferred currency in Cuba, and those who earn pesos, the
 official currency.

 Sociologists now talk of an emerging middle class whose ranks are filled not by doctors and
 lawyers, but by taxi drivers and hotel workers who are among the 45 percent of the population with
 access to US dollars. Their new buying power allows them to shop in US dollar stores - the only
 place where items such as televisions and imported shampoo are available.

 The new system's effects became apparent quickly. Before dollarization, the wealthiest Cubans
 made four times as much as the poorest. By 1994, that gap widened even further, according to a
 1998 study by Cuban sociologist Mayra Paula Espina, who wrote the report for the Center for
 Psychological and Sociological Investigation, a respected Cuban government policy group.

 The study also found that in 1994, less than 10 percent of the population owned 60 percent of the
 wealth and 70 percent of bank deposits came from 6 percent of savers.

 The government is not blind to the problem. In the early years of dollarization, known as the special
 period, President Fidel Castro called on Cubans to be patient, saying it was only a matter of time
 before the island's economy rebounded and the new wealth created by tourism would spread.

 After a brief upturn, the economy has nosedived with the slump in tourism following the Sept. 11
 terrorist attacks in the United States and the worldwide recession. The government announced
 plans last month to shut down half of the island's sugar mills - once the economic staple that
 employed more than 400,000 people.

 Many analysts say it is only a matter of time before economic woes trigger serious political unrest.
 ''There is a great deal of tiredness because of the economic situation, and in the long term, that's a
 problem for the Cuban government,'' said Geoff Thale, a specialist on Cuba with the Washington
 Office on Latin America.

 Thale cited the Varela Project, a resistance campaign in which Cuban dissidents collected more
 than 10,000 signatures to force a referendum on democratic reforms on the communist-run island,
 as an example of the growing discontent. The project was supported by former US president
 Jimmy Carter, who endorsed it during a nationwide televised address in Cuba in May.

 To correct some of the growing income disparities, Castro recently announced price hikes on US
 dollar goods to try to redistribute the wealth generated by the new dollar economy. But many
 residents doubt there will be much change. ''We have no choice. There are doctors working
 cleaning houses. Engineers.'' said Zoraida, a 52-year-old warehouse manager who took a part-time
 job cleaning the house of a wealthier neighbor. She spent her first $10 monthly paycheck on
 shampoo, a bottle of face lotion, and a package of liver for herself and her two children.

 ''Now, everyone is looking to get work as a maid,'' she said, as she prepared a lunch of grilled
 chicken, vegetables, and rice for her new employers. ''It's the only way to get by. Do we feel bad
 about it? No way. We feel better because we earn more.''