Harlem — For months, Christopher Zambakari has watched online as the U.S. dollar's value declined – especially its relation to the Ugandan shilling. A 22-year-old foreign student living in Manhattan, Zambakari and his mother regularly wire money to Uganda to support 15 relatives there. And while his classmates at the European School of Economics in Midtown rejoice at the strength of the Euro or the British pound, the dollar's weakness means trouble for the MBA student's family in Africa.

Like so many New York City residents, workers and students from other countries, the money that Zambakari sends home, called remittances, is essential to his family's welfare. People residing in the U.S. sent a total of $42 billion to their homes around the globe in 2006, according to the World Bank – but the falling worth of the dollar is making it harder to provide for loved ones. Over the seven years Zambakari and his mother have lived in the U.S., each dollar has translated into fewer shillings – nearly 2,000 in 2004, for example, versus 1,575 shillings last summer.

The effect is disturbingly concrete for Zambakari and his mother, who works caring for elderly people in Tucson. They are from the Sudan, but in hopes of receiving a better education their relatives moved to Uganda, where the education system is mostly privatized. The falling dollar has coincided with a tuition increase, and Zambakari's teenage brother Timothy recently had to miss school.

“Since 2008, my little brother has had to sit out the whole first trimester because there was no money,” Zambakari said. His relatives rely almost exclusively on Zambakari and his mother to pay for food, water, medicine, school fees, electricity and rent. Uganda suffers from a high unemployment rate, and Zambakari’s Sudanese relatives find it very difficult to generate an income in their new home. As the dollar depreciated, Zambakari’s uncle, two aunts, and three cousins had to move back to Sudan in the past year, finding it impossible to live on the dollars that Zambakari and his mother anxiously sent home through Western Union.

“We couldn’t pay for food, we couldn’t pay for school, they were starving,” Zambakari said. “They were worse off in Kampala than they were in Sudan. Last year, $150 a month would have been enough to feed everyone. Now the same sack of rice is twice as much as it was before."

When Zambakari sends money home – which is often, considering that he has no income apart from student loans – he travels to what he calls "Little Senegal," a West African community in Harlem. There, he can purchase African Night phone cards – $2 for 30 minutes of air time to Uganda – and visit the Western Union on Frederick Douglass Boulevard. The yellow-and-black Western Union signs and the bilingual advertisements to make money available in minutes are fixtures of any immigrant community in the five boroughs. Whether immigrants send money home through Western Union or its competitor Money Gram, they have common goals: Send as much money home as possible and keep transfer fees low.

On 39th Street in Sunnyside, Queens – a neighborhood that's home to many immigrants from Central and South America, Asia, and Europe – several shops that offer money transfer services line the road. Residents can walk down the stairs from the 7 train subway stop, visit the Pay-o-Matic Western Union, and get a haircut at Los Maestros barber shop, or purchase a phone card to call relatives in Colombia. Customers recently said they are concerned to see the dollar depreciating.