Employing this particular technique meant that Hoxby’s results depended crucially on her measurement of the streams. It is these measurements, and Rothstein’s own measurements of the streams, that are at the center of the academic dispute between the two economists.

Rothstein has said that his attempts to replicate Hoxby’s results using her streams data has proved unsuccessful, which has led him to argue that Hoxby’s conclusions are overstated.

In his 2004 working paper, Rothstein argued that Hoxby’s analysis contained a series of errors in data and computer code, casting her results into question. He contended that by using different models, the effect of school choice remained near zero—a discrepancy that would invalidate Hoxby’s conclusion that competition has a positive impact on school quality.

“What worries me most about the results is that they are so sensitive,” Rothstein said. “You get such differences in the results when you make minor changes.”

In her response to Rothstein, Hoxby denounced each of Rothstein’s major claims, calling his arguments “wrong”, “misleading”, and “not credible,” even venturing that Rothstein “may suffer from…confusion.”

“The comment is not a replication, and each of its points is incorrect,” she wrote in her March paper.

‘IDEOLOGICAL BIAS’?

Hoxby said she believes that Rothstein’s interest in her work—and his working paper—have been instigated by the “ideological bias” of Rothstein’s dissertation adviser, Card. She said she believes there may be a larger issue of prejudice underlying the entire debate.

“I think there is quite a lot of race and gender bias going on here,” Hoxby said in an interview with The Crimson. “I think it’s really a pity. I think there are a few people being very unreflective about their behavior.”

Neither Rothstein nor Card would directly address the accusations of bias.

“I won’t dignify…[those] questions with responses,” Rothstein wrote in an e-mail. “My work speaks for itself.”

Princeton economics professor Cecilia E. Rouse ’86 completely dismissed Hoxby’s accusations.

“Quite frankly, I think it’s pretty outrageous,” Rouse said. “Everything I know about Professor Rothstein suggests that that was not at all his motivation.”

DATA DEBATE

Aside from the content of the papers, Rothstein’s implication that Hoxby violated a long-standing AER policy by initially refusing to publicize her data has sparked the interest of some in the field.