BRAZIL:  Maria Rodrigues Ferreira Rocha, mother of Jefferson (seated) and Marta, works at a charcoal kiln in Grao Mogol. She says she has been a slave since age five.

BENIN:  Constant Ayitcheou, age 13, says he was trafficked at eight years old by a friend of his father. Promised education and money, he was instead taken to become a domestic servant in Nigeria. "PAFAJESD" is the French acronym of the aid organization that helped to free him.

SUDAN:  Akuac Malong (left), age 13, walks home to her village, Madhol, in southern Sudan. She says she was kidnapped and held for seven years as a domestic slave in northern Sudan.

MACEDONIA:  Tanja, age 24, sits in a refugee center in Skopje. She escaped from prostitution after ethnic Albanian guerrillas raided the bar where, she says, she was enslaved. She is waiting to return to her native Moldova.

For Meera, the revolution began with a single rupee. When a social worker came across Meera's unmapped village in the hills of Uttar Pradesh in India three years ago, he found that the entire population was in hereditary debt bondage. It could have been in the time of their grandfathers or great-grandfathers--few in the village could remember--but at some point in their past, the families had pledged themselves to unpaid labor in return for loans of money. The debt passed down through the generations. Children as young as five years old worked in quarry pits, making sand by crushing stones with hammers. Dust, flying rock chips and heavy loads had left many villagers with silicosis and injured eyes or backs.

Calling together some of the women, the social worker proposed a radical plan. If groups of 10 women agreed to set aside a single rupee a week from the tiny sums the moneylenders gave them to buy rice, he would provide seed money and keep the funds safe. Meera and nine others formed the first group. The rupees slowly mounted up. After three months, the group had enough to pay off the loan against which Meera was bonded. She began earning money for her work, which greatly increased the amount she could contribute to the group. In another two months, another woman was freed; the following month, a third came out of bondage.

At that point, the other members, seeing that freedom was possible, simply renounced their debts and declared themselves free. The moneylenders quickly moved against them, threatening them and driving them from the quarries. But the women were able to find jobs in other quarries. New groups followed their example. The social worker has taken me to the village twice, and on my second visit, all its inhabitants were free and all their children in school.

Less than 100 kilometers away, the land turns flat and fertile. Debt bondage is common there, too. When I met Baldev in 1997, he was plowing. His master called him "my halvaha," meaning "my bonded plowman." Two years later I met Baldev again and learned that because of a windfall from a relative, he had freed himself from debt. But he had not freed himself from bondage. He told me:

After my wife received this money, we paid off our debt and were free to do whatever we wanted. But I was worried all the time--what if one of the children got sick? What if our crop failed? What if the government wanted some money? Since we no longer belonged to the landlord, we didn't get food every day as before. Finally, I went to the landlord and asked him to take me back. I didn't have to borrow any money, but he agreed to let me be his halvaha again. Now I don't worry so much; I know what to do.

Lacking any preparation for freedom, Baldev reenrolled in slavery. Without financial or emotional support, his accidental emancipation didn't last. Although he may not bequeath any debt to his children, his family is visibly worse off than unbonded villagers in the same region.

To many people, it comes as a surprise that debt bondage and other forms of slavery persist into the 21st century. Every country, after all, has made it illegal to own and exercise total control over another human being. And yet there are people like Baldev who remain enslaved--by my estimate, which is based on a compilation of reports from governments and nongovernmental organizations, perhaps 27 million of them around the world. If slaveholders no longer own slaves in a legal sense, how can they still exercise so much control that freed slaves sometimes deliver themselves back into bondage? This is just one of the puzzles that make slavery the greatest challenge faced by the social sciences today. Despite being among the oldest and most persistent forms of human relationships, found in most societies at one time or another, slavery is little understood. Although historians have built up a sizable literature on antebellum American slavery, other types have barely been studied. It is as if our understanding of all arachnids were based on clues left by a single species of extinct spider. In our present state of ignorance, we have little hope of truly eradicating slavery, of making sure that Meera, rather than Baldev, becomes the model.

The New Slavery

Researchers do know that slavery is both evolving and increasing in raw numbers. Like spiders, it permeates our world, typically hidden in the dark spaces of the economy. Over the past few years, journalists and activists have documented numerous examples. Human trafficking--the involuntary smuggling of people between countries, often by organized crime--has become a huge concern, especially in Europe and Southeast Asia. Many people, lured by economic opportunities, pay smugglers to slip them across borders but then find themselves sold to sweatshops, brothels or domestic service to pay for their passage; others are kidnapped and smuggled against their will. In certain areas, notably Brazil and West Africa, laborers have been enticed into signing contracts and then taken to remote plantations and prevented from leaving. In parts of South Asia and North Africa, slavery is a millennia-old tradition that has never truly ended.

The plight of these people has drawn the attention of governments and organizations as diverse as the Vatican, the United Nations, the International Organization for Migration, and Amnesty International. Two years ago the U.S. government established a central coordinating office to deal with human trafficking. Academic researchers are beginning to conduct intensive studies. The anecdotal and journalistic approach is slowly transforming into the more rigorous inquiry of social science. For example, Urs Peter Ruf of the University of Bielefeld in Germany has documented the evolution of master-slave relations in modern Mauritania. Louise Brown of the University of Birmingham in England has studied women forced into prostitution in Asia. David Kyle of the University of California at Davis and Rey Koslowski of Rutgers University have explored human smuggling. I have posited a theory of global slavery and tested it through case studies in five countries.

A common question is why these practices should be called slavery rather than just another form of superexploitation. The answer is simple. Throughout history, slavery has meant a loss of free will and choice backed up by violence, sometimes exercised by the slaveholder, sometimes by elements of the state. That is exactly what other researchers and I have observed. Granted, workers at the bottom of the economic ladder have few options to begin with, but at some point on the continuum of exploitation, even those options are lost. These workers are unable to walk away.

Human suffering comes in various guises, yet slavery has a distinctive horror that is evident to those of us who have seen it in the flesh. Even when it does not involve beating or other physical torture, it brings about a psychological degradation that often renders victims unable to function in the outside world. "I've worked in prisons and with cases of domestic violence," says Sydney Lytton, an American psychiatrist who has counseled freed slaves. "This is worse."

Although each of the manifestations of slavery has unique local characteristics, one of the aims of social scientists is to understand their universal features, so that therapies developed in one place can be applied elsewhere. Foremost among these commonalities is the basic economic equation. In 1850 an agricultural slave cost $1,500 in Alabama (around $30,000 in today's dollars). The equivalent laborer can be had for around $100 today. That payment might be made as part of a "loan" or as a "fee" to a trafficker. A young woman in Southeast Asia or eastern Europe might be sold several times, through a series of brokers and pimps, before she ends up in a brothel.

Throughout HISTORY, slavery has meant a loss of free will and choice backed up by VIOLENCE, sometimes exercised by the slaveholder, sometimes by elements of the state.

One should not read too much into these specific dollar amounts, because what the slaveholder purchases is somewhat different in each case. The basic point is that forced labor represents a much smaller percentage of business expenses than it used to. It took 20 years of labor for an antebellum American slave to repay his or her purchase price and maintenance costs; today it takes two years for a bonded laborer in South Asia to do the same. This fall in price has altered not only the profitability of slavery but also the relationship between slave and master. The expensive slave of the past was a protected investment; today's slave is a cheap and disposable input to low-level production. The slaveholder has little incentive to provide health care or to take care of slaves who are past their prime.

Several trends could account for this shift. The world's population has tripled since World War II, producing a glut of potential slaves. Meanwhile the economic transformation of the developing world has, whatever its benefits, included the loss of community and social safety nets, matched by the erection of vast shantytowns. But the vulnerability of large numbers of people does not make them slaves; for that, you need violence. The key factor in the persistence of slavery is the weak rule of law in many regions. Widespread corruption of government and police allows violence to be used with impunity even when slavery is nominally illegal.

In spite of the violence, and the living and working conditions, people in slavery have their own mental integrity and their own mechanisms for surviving. Some may actually like different aspects of their life, perhaps the security or their understanding of the order of things. When you disrupt this order, suddenly everything is confused. Some of the women who were freed have attempted suicide. It is easy to assume that this happened because of the abuse they had lived through. But for some of these women, slavery had been the major psychological building block in their lives. When that was destroyed, the meaning of their life was like a bit of paper crushed up and thrown away. They were told: "No, this is not the way it is supposed to be. Start all over again." It was as though their life had no meaning.

Plausible Deniability

Human-rights worker Vivek Pandit of the Vidhayak Sansad organization in India has been liberating bonded laborers for more than 20 years. He is adamant that real liberation takes place in the mind, that physical freedom isn't enough--as was the case with Baldev. Conversely, mental freedom can bring about physical freedom--as it did for Meera.

Pandit's organization has devised a program of education that prepares former bonded laborers for a life of freedom. They are taught basic science to promote their curiosity and attention to detail; role-playing to stimulate problem solving; and games to develop strategic thinking and teamwork. This training comes after a challenging public dialogue in which the laborer recounts and renounces his or her bondage. The renunciation is recorded and read out in the village. "When the ex-slave has fixed his thumbprint to this public document," Pandit says, "they can't go back."