It's part of an estimated $1.1 billion (R9.9 billion) sent to Cubans last year by relatives and friends around the world, an amount equal to about 1.8 percent of the communist country's 2007 gross domestic product
"Most of the remittances end up used for consumption," said Gonzalez-Corzo's son Mario, a Cuban-born assistant economics professor at Lehman College in New York, who has studied remittances and provided the estimates. "It helps."
The money also helps the island's $58 billion economy, as the Cuban government charges fees that take about 20 percent of exchange-wired dollars, says Gonzalez-Corzo.
Funding Castro
That troubles US politicians who say the transfers support the totalitarian state created by Fidel Castro in 1959 and now run by his brother Raul. US President Barack Obama this week eased restrictions that had limited money transfers by Cuban-Americans, most of whom live in southern Florida.
"The Castro government will confiscate a high percentage of those dollars, further propping up a regime that suppresses human rights," said Kendrick Meek, a Democrat representing parts of Florida's Miami-Dade and Broward counties.
About 735 000 people around the world - more than half from the US - sent an average of $150 to Cuba last year, according to a study by Inter-American Dialogue, a Washington-based research organisation. The cash sent in 2007 was equal to 42 percent of the island's tourism income and 4.7 times more than its sugar exports, Gonzalez-Corzo said.
"Remittances are a key component to the Cuban economy," where state wages averaging about $17 a month don't cover basic living expenses, says a study released last month by Inter-American Dialogue. "Cubans typically augment state wages with hard-currency obtained remittances."
That's why Myriam Faya and Lourdes Rodriguez, sisters who are among the 795 000 Cuban-Americans in Miami-Dade County, the largest concentration outside Cuba, send money to the island.
"I have an aunt who is 87 years old and her pension is very low so we send regularly, without any doubt, $50 a month," said Faya, who works for an insurance broker.
Money mules
About 60 percent of the money sent to Cuba goes via electronic wire transfer, according to the Inter-American Dialogue study. The rest travels in the pockets of visitors.
These mulas, Spanish for mules, bypass the government fees.
"If you send by wire, it's very expensive because the government takes 20 percent," Faya said. "But if a friend goes there, you can give it to them."
On the other end are charges by transfer agents. Calls to wire services in Miami found fees of as much as 24 percent.
The national average is 15 percent per $100, Gonzalez-Corzo says. Including what Cuba charges, the transaction cost for $100 becomes 35 percent. That's more than the 5.8 percent cost for money wired to Mexico and the 9.5 percent for the Dominican Republic, data from the World Bank show.
"Cuba is the most expensive remittance market in the world when it comes to the transaction cost," Gonzalez-Corzo says.
Under rules imposed under former president George W Bush in June 2004, money sent to Cuba could go only to immediate family members and the amount was capped at $300 each quarter. Travelers could carry only $300 into the country.
Obama granted unlimited transfers and travel cash for Cuban-American families to anyone in Cuba, which is expected to reduce transfer costs as competition grows, Gonzalez-Corzo says.
The president's action raised optimism among investors that other parts of the US economic embargo against Cuba could be lifted.
Booming business
The Herzfeld Caribbean Basin Fund, a closed-end mutual fund of companies that could benefit from increased business with Cuba, rose 41 percent, the most ever, the day money transfers were eased.
Companies that wire money to Cuba must be licensed by the US Treasury's Office of Foreign Assets Control (Ofac), under economic sanctions imposed in 1963 after Fidel Castro established his communist dictatorship. Fidel Castro turned over power to Raul Castro last year because of illness.
More than 100 companies are authorised by Ofac, with 75 of them in Florida. The largest is Western Union, the world's biggest money-transfer business.
The firm has been active in Cuba since 1999 and has 153 agents there, says Stewart Stockdale, president for the Americas.
"We think lifting the restrictions is going to expand the business to Cuba significantly," he says. Western Union charges $15 to wire amounts up to $100 to Cuba.
The fees are "something we're reviewing", he adds.
Gonzalez-Corzo favours anything that makes it easier for him to send money to his 70-year-old father in Santa Clara, in central Cuba.
"I have personally gone through all the tribulations of sending money," he said. "So I know how it works." - Bloomberg