That trouble is about not paying bills. It’s also about the vertigo of falling out of the middle class. “We talk about it as middle-class poverty,” said Sara Horowitz, founder and executive director of the Freelancers Union, which has 70,000 members in New York City. “Your frame of reference, when you think of yourself as middle class, doesn’t include being scared about making ends meet, realizing that welfare and food stamps are your only option. Psychologically, that shift is devastating.”

Image For more than four years, Lisa Feuer was able to make ends meet as a freelance yoga instructor. The recession, however, has severely curtailed business. Credit... Michal Chelbin for The New York Times

Sudhir Venkatesh, a sociologist who teaches at Columbia University, began to see early signs of that shift last winter in the coffee shops where he does fieldwork. Venkatesh is collecting work histories in the course of studying the off-the-books economy: in a chapter of Stephen J. Dubner and Steven D. Levitt’s book “Freakonomics,” he was the clever Ph.D. student who noticed that many drug dealers lived with their mothers because they couldn’t afford their own housing.

Venkatesh observed that when the recession began, the spectrum of vulnerability among freelance workers broadened, from the sex workers he is currently studying to those in other professions. Every few months, Venkatesh goes to the same set of coffee shops in Manhattan and Brooklyn and talks to people who come in and sit down. “I’m looking for clues in weird places that won’t register for an economist,” he says. Venkatesh asks the coffee-shop patrons whether they are out of work, looking for work or have stopped looking in the past few weeks.

Venkatesh also asks people if they work for themselves. Over the years, he has observed the rise in the number of people who say yes. This year, he estimated, at least half of his coffee-shop sample was made up of the self-employed. Increasingly, they talk about their fading prospects. In 2005, 16 percent of the coffee-shop patrons Venkatesh talked to in Brooklyn and 34 percent in Manhattan said they were out of work, were looking or had recently given up looking. In April of this year, the figure rose to 37 percent in Brooklyn and spiked to 53 percent in Manhattan. Many of the coffee-shop patrons told Venkatesh that they had maxed out their credit cards and had no savings. He concluded that it wasn’t just many workers in the sex industry who were living at the edge of poverty — it could be anyone who had hung out their own shingle.

Venkatesh sees a difference in how freelancers talk about the recession compared with workers who have been laid off. “They’re more alone, and they can’t help but feel like they did something wrong because they’re losing relationships with individual clients,” he says. “They think of themselves as ministering to their clients, so they also feel guilty about no longer helping them.”

The instability of freelancing isn’t new. Lawrence Katz, a Harvard economist, points out that the share of workers who have standard full-time jobs with benefits has been shrinking since the 1980s. But in the past, temporary and on-call workers — everyone from data-entry employees to construction workers — were hit hardest by downturns. Now the higher-earning independent contractors are suffering, too. Meanwhile, unemployment insurance is still largely structured as it was when the system was instituted during the Depression. “Unemployment insurance was designed in 1935 to give temporary support to the classic male laid-off worker,” Katz says. “It’s not set up for the circumstances we see today, with a lot of people freelancing.”

President Obama’s recovery package includes incentives for states to modernize their unemployment-insurance laws by, among other things, covering more part-timers. “But it’s still tough for freelancers,” Katz says. At the Freelancers Union, Sara Horowitz is pushing for a new kind of unemployment protection fund that would cover the self-employed by helping them put away money that they could draw on in times of need.