– The Associated Press

CHICAGO – Robert W. Fogel, a University of Chicago economist whose study of the economics of slavery sparked a furious debate in academia and later helped garner him a Nobel Prize, has died. He was 86.

The university announced that Fogel died on Tuesday, reporting that the family said he died after a brief illness.

Fogel wrote 22 books in all — the last one published in April — and, according to the school, was an active faculty member in the department of economics and the Booth School of Business who was working on three more books at the time of his death.

Fogel first rose to prominence among economists in the early 1960s when as a Ph.D. student at Johns Hopkins University he conducted a statistical analysis of the impact railroads had on the nation’s economy in the 19th century.

That led to a book, “Railroads and American Economic Growth: Essays in Economic History,” in which he contended that the railroads had a far smaller impact on the economy than was widely believed at the time.

But it was his work on slavery that brought Fogel the most attention. In “Time on the Cross: The Economics of American Negro Slavery,” a book published in 1974, Fogel and co-author Stanley Engerman “challenged the long-held assumption, by then taken as fact, that slavery was unprofitable, inefficient and in decline in the years leading up to the Civil War,” according to an article released by the school.

Instead, Fogel and Engerman concluded that farms where slaves were used were as productive as those where they weren’t.