From a results standpoint, the hunger strike was a success. On the ninth day, as four frazzled, dehydrated and disoriented students continued their public protest of the wages paid to some Stanford University workers, the administration gave in: All contracted employees, even those who work less than 30 hours a week, would be covered by the university's "living wage" policy, which was established for full-time employees in 2003.
The announcement  came on April 20. Just two days later, students at the University of Vermont started a hunger strike of their own, for similar reasons. That ended five days later  in a promise from the university to reevaluate its wage policy and establish a permanent task force on employee compensation.
Now, students at Harvard University will see if similar tactics could prod their own administration. On Wednesday, a second student was briefly hospitalized  with low sodium levels on the seventh day of a hunger strike -- again, a wage dispute, this time for security guards. Earlier in the week, another student was hospitalized and eventually forced to stop fasting for health reasons.
Harvard's activists were joined on Wednesday by the fourth hunger strike in less than a month , spread out among three University of California campuses, where students began starving themselves to protest the university system's involvement in nuclear research.
Hunger strikes are hardly unusual on college campuses; a major one in December  lasted for 27 days at Purdue University, and even a professor recently used the tactic to call attention to his tenure fight  at the Massachusetts Institute of Technology. This recent convergence of protests on campuses across the nation, all using similar tactics and within such a short period of time -- three for wage-related issues -- might hint at a possible consensus among student groups about what methods are most effective when dealing with university administrations. Or, they might say something about the desperation felt by many university labor activists who have been involved in various years-long campaigns for higher employee wages.
Whatever these protests signal, two things are certain: The students at different campuses are aware of each other, and umbrella groups, if not explicitly organizing a national campaign, are providing some measure of advice and support to campus organizations.
"We've definitely been working more and more with campuses that have been doing living wage campaigns," said Carlos Jimenez, a national coordinator with the Student Labor Action Project . But he stressed that the organizing is happening on individual campuses.
So why now? It may be tempting to explain away the phenomenon with talk of tipping points, maybe even the wisdom of crowds. One professor speculated that it might be a manifestation of social contagion.
Donald Downs, a professor of political science at the University of Wisconsin at Madison who has studied the dynamics of student protests in the past, invoked a theory from an out-of-print book from 1973 called The Radical Probe: The Logic of Student Rebellion , by Michael W. Miles (who died in 1996). It discusses student activism in terms of "contagion theory," in which a core "vanguard group" spreads their message until it encompasses major support on campus.
Downs said that the Cornell University building takeover in 1969, which he wrote a book about, epitomized that model. He suggested that the hunger strikes now or recently underway could be an "example of the contagion theory applied more broadly," nationwide. (Or even internationally: Parents of a Harvard activist in Ontario pledged to fast for a day in solidarity with their daughter .)
"Clearly, because of the modern world and Googling and the Internet, everyone knows what everyone else is doing," Downs said. Jimenez suggested the same: "It's kind of picked up an intensity, students have been seeing that other students have been doing sit-ins" or other forms of activism.
While there may be a social component to the spike in recent incidents, there might also be the more mundane explanation. "These are campaigns that have been building up now for years in a lot of these institutions," Jimenez said.
At Harvard, the dispute can be traced to a 2001 sit-in that ended with the creation of a committee  designed to investigate wage policy for lower-income employees. Joe Wrinn, a spokesman for the university, said that a "wage parity program" was created the next year, resulting in yearly audited standards for low-wage and contracted workers.
Currently, a security contractor that provides employees to Harvard, AlliedBarton, is in negotiations with its unionized workers. The union, Service Employees International Union 615, "essentially brought the campaign to the students," said Harvard sophomore Lucy MacKinnon, a spokeswoman for the Student Labor Action Movement, the student group organizing the hunger strike. Harvard has repeatedly called the dispute one between a private company and its workers and says it will not intervene.
Students at Harvard felt the need to act immediately because of the looming end of the semester and the ongoing negotiations. "I think in a lot of ways it was about ... beginning a campaign quickly and putting on a lot of pressure quickly," MacKinnon said. "Whether or not this is a good tactic ... that's still to be seen."
Matt Seriff-Cullick, a junior at Stanford who took the quarter off to help organize the hunger strike there and negotiate with the administration, emphasized that while he was aware of efforts at other campuses and national groups (like United Students Against Sweatshops  and Student Labor Action Project), the decision to act was their own.
Daniel Weissman, a Stanford graduate student who went to Harvard for his bachelor's degree, said there was no coordination between groups at the two campuses. But they keep each other up to date. He notified students at Harvard when the hunger strike began at Stanford, and he heard about the Harvard strike as soon as it started. One graduate student who fasted at Stanford, also a former undergrad at Harvard, spoke there recently during their hunger strike.
"There's starting to be more coordination along those lines, I think," Jimenez said. "Students are really energized. We kind of see that this is going to be picking up in intensity next year."
Last month, students occupied the president's office  at the University of Southern California with demands that the administration revise its policies on branded apparel made with sweatshop labor. The effort ended the same day with threats to suspend the students and calls to their parents.
Hunger strikes, in contrast to sit-ins, disrupt only the lives of the students who starve themselves. And that might mean the tactic is starting to be favored among activists.
"In the post-9/11 world, activists have had to beware that their actions not be linked, in the public eye, with anything that smacks of terrorism," said Ben Berger, a professor of political science at Swarthmore College who studies civic engagement, in an e-mail. "Hostile takeovers of university buildings or other acts of organized violence run that risk. Not so with hunger strikes, which threaten only the protesters as they attempt to demonstrate publicly their moral seriousness."
Hunger strikes have the added benefit of being associated with peaceful (and sometimes religiously influenced) social movements in the past. "In my view it fits into a broad historical trend," said Philip G. Altbach, the Monan professor of higher education at Boston College. "Students have engaged in hunger strikes way back; during the civil rights movement there were hunger strikes that occurred."
Philosophically, too, it makes sense that students protesting labor conditions for workers would use a tactic that publicly showcases the consequences of scarcity -- an especially visible juxtaposition at a campus like Harvard.
"At a university with so much wealth, having people stop eating is a pretty radical tactic," MacKinnon said. Seriff-Cullick, at Stanford, analyzed the message of a hunger strike in similar terms. "After four years of delays, rationalizations, obfuscations and unfulfilled promises, the hunger strike calls attention to every single day that workers go without a wage sufficient to support themselves and their families, every single day that students go without a voice that is recognized on campus -- because every one of those days translates into a day without any food for 12 students whose voice will not go unrecognized."
But beyond philosophical and moral justifications, there are practical considerations as well. Hunger strikes might, at least in the present context, be more effective -- especially in the post-9/11 atmosphere invoked by Berger. The Stanford and Vermont strikes each ended with at least a pledge to look into the issue; the Purdue one did not. At Harvard and UC, it may come down to a test of will.
There's one other common factor among all the hunger strikes: they involve a relatively small number of students. At Harvard, 11 initially said they would fast; at Stanford, four made it to the end. "What you get, probably, is more bang for the buck," Downs said. "You don’t need to have a larger movement [necessary] to take over a building or take over an office."
Hunger strikes "test publicly the administration's moral seriousness, because they force administrators to make a public choice between a policy stance and the protesters' welfare," Berger said.