In her study, "The Return to Attending a More Selective College: 1960 to the Present," Hoxby showed that attending a top-tier school does pay off in the long run. But Hoxby's definition of a top-tier school was more inclusive than that of Krueger and Dale--her top tier included their system's top three tiers.

"The schools surveyed by Krueger and Dale didn't have much difference in cost. They were looking at the top 1 percent," Hoxby said.

Samuelson, who concentrated in government at Harvard in the mid-1960s, said he's not sure whether or not attending a top-tier college strongly affected his earnings after graduation.

"You make or break the situation yourself," he said. "I tell my kids it's what you do and what you know, not where you go that counts."

Krueger, who earned his Ph.D. from Harvard in 1987, said that another Harvard professor recently challenged his study during a conference. The professor wondered how Harvard students could not have an edge when their professors are of such a high caliber.

Krueger answered that the access of students to high-quality resources at schools of similar costs is fairly uniform.

"I asked him when was the last time he taught undergraduates," Krueger said. "And he couldn't remember."