But such pronouncements were overly optimistic, for homesickness continued to plague many who migrated.

Today’s technologies have also failed to defeat homesickness even though studies by the Carnegie Corporation of New York show that immigrants are in closer touch with their families than before. In 2002, only 28 percent of immigrants called home at least once a week; in 2009, 66 percent did. Yet this level of contact is not enough to conquer the melancholy that frequently accompanies migration. A 2011 study published in the Archives of General Psychiatry found that Mexican immigrants in the United States had rates of depression and anxiety 40 percent higher than nonmigrant relatives remaining in Mexico. A wealth of studies have documented that other newcomers to America also suffer from high rates of depression and “acculturative stress.”

Ricardo Valencia, an immigrant from Guadalajara, puts a face to such statistics. In 2005, he traveled to Nevada to work so he could pay off a mortgage on his house. The day after he arrived in Nevada, he thought, I want to leave! As he explained to me: “I’ve always been really close with my family. ... I had to stand it, we had to stand it ... but returning was always in mind.” He used e-mail and phone cards to keep in touch with his wife, calling her several times a week. But even this regular communication could not assuage his tremendous homesickness. He finally returned to his family in 2009.

Like Mr. Valencia, 20 to 40 percent of all immigrants to the United States ultimately return to their native lands. They know that Skype is no substitute for actually being there.

It is possible that these new technologies actually heighten feelings of displacement. María Elena Rivera, a psychologist in Tepic, Mexico, believes technology may magnify homesickness. Her sister, Carmen, had been living in San Diego for 25 years. With the rise of inexpensive long-distance calling, Carmen was able to phone home with greater frequency. Every Sunday she called Mexico and talked with her family, who routinely gathered for a large meal. Carmen always asked what the family was eating, who was there. Technology increased her contact with her family but also brought a regular reminder that she was not there with them.

The immediacy that phone calls and the Internet provide means that those away from home can know exactly what they are missing and when it is happening. They give the illusion that one can be in two places at once but also highlight the impossibility of that proposition.

The persistence of homesickness points to the limitations of the cosmopolitan philosophy that undergirds so much of our market and society. The idea that we can and should feel at home anyplace on the globe is based on a worldview that celebrates the solitary, mobile individual and envisions men and women as easily separated from family, from home and from the past. But this vision doesn’t square with our emotions, for our ties to home, although often underestimated, are strong and enduring.