This is one of the best books I've ever read on American negro slavery. What makes it a valuable edition to the academic literature is that the authors did not go into this with any ideological axes to grind. Indeed, both are political liberals who thoroughly deprecate the institution of slavery as a social and moral evil. They simply wanted to attain a better understanding of the actual economics of slavery in the Old South by analyzing the Plantation Books (i.e. the financial logs of Southern planters) and other relevant statistical resources so as to be able to accurately assess what slavery was like and how it affected the slave, the master and Southern society as a whole.
Much to their surprise, the authors concluded that slavery, as it was, bore little resemblance to the fictional, fever-swamp, nonsense that is peddled by the NAACP, the liberal media, Steven Spielberg, Oprah Winfrey and left-wing academics. They found that slaves had a better diet and better housing conditions than their wage-slave, immigrant counterparts in the North. They also found that slave families were rarely broken up and that miscagenation between masters and slaves was exceeedingly rare -- indeed, almost nonexistant. They also found that many slaves earned substantial incomes - a fact that surprises many people who believe that slaves did not earn money for their labour. I could go on and on but that would give away the book and ruin the joy of reading a text that absolutely blows away virtually all the "conventional wisdom" you've ever heard repeated about slavery in the Old South.
Anyone who really wants to learn the truth about slavery owes it to themselves to buy and read this book.