Compared to historical slavery

Modern slavery

Although slavery is illegal in every country in the modern world, it still exists, and even on the narrowest definition of slavery it's likely that there are far more slaves now than there were victims of the Atlantic slave trade.

The last country to abolish slavery was the African state of Mauritania, where a 1981 presidential decree abolished the practice; however, no criminal laws were passed to enforce the ban. In August 2007 Mauritania's parliament passed legislation making the practice of slavery punishable by up to 10 years in prison.

Richard Re, writing in 2002, stated:

Conservative estimates indicate that at least 27 million people, in places as diverse as Nigeria, Indonesia, and Brazil, live in conditions of forced bondage. Some sources believe the actual figures are 10 times as large. Richard Re, A Persisting Evil: The Global Problem of Slavery, Harvard International Review, 2002

Changes

Modern slavery differs from historical slavery in several ways:

There are more slaves than ever before, but they are a smaller proportion of the human race

No-one seriously defends slavery any more

Slavery is illegal everywhere and so requires corruption and crime to continue. The power of the slave owner is always subject to the power of the state; slavery can only continue to exist if governments permit it to, and some writers claim that government corruption is a leading cause of the persistence of slavery

Slaves are cheaper than ever and can generate high economic returns. Modern slavery is very cheap, and Kevin Bales has argued that this has made modern slavery even worse than that of Atlantic Slave Trade:

In the United States before the Civil War, the average slave cost the equivalent of about fifty thousand dollars. I'm not sure what the average price of a slave is today, but it can't be more than fifty or sixty dollars. Such low prices influence how the slaves are treated. Slave owners used to maintain long relationships with their slaves, but slaveholders no longer have any reason to do so. If you pay just a hundred dollars for someone, that person is disposable, as far as you are concerned... And while the price of slaves has gone down, the return on the slaveholder's investment has skyrocketed. In the antebellum South, slaves brought an average return of about 5 percent. Now bonded agricultural laborers in India generate more than a 50 percent profit per year for their slaveholders, and a return of 800 percent is not at all uncommon for holders of sex slaves. Interview with Kevin Bales, 2001

No industry depends on slavery in the way that the plantations did in the times of the Atlantic slave trade