NASHVILLE, TENN., Jan. 27, 2007 — Light-skinned immigrants in the U.S. make more money on average than those with darker complexions, and the chief reason appears to be discrimination, a researcher says.

Joni Hersch, a law and economics professor at Vanderbilt University, looked at a government survey of 2,084 legal immigrants to the U.S. from around the world and found those with the lightest skin earned an average of 8 percent to 15 percent more than similar immigrants with much darker skin.

"On average, being one shade lighter has about the same effect as having an additional year of education," Hersch said.

The study also found that taller immigrants earn more than shorter ones, with an extra inch of height associated with a 1 percent increase in income.

Hersch took into consideration other factors that could affect wages, such as English-language proficiency, education, occupation, race or country of origin, and found that skin tone still seemed to make a difference in earnings.

That means that if two similar immigrants from Bangladesh, for example, came to the U.S. at the same time, with the same occupation and ability to speak English, the lighter-skinned immigrant would make more money on average.

"I thought that once we controlled for race and nationality, I expected the difference to go away, but even with people from the same country, the same race — skin color really matters," she said, "and height."

Although many cultures show a bias toward lighter skin, Hersch said her analysis shows that advantage was not the result of preferential treatment in the country of origin.

The bias, she said, occurs in the U.S.

Hersch drew her data from a 2003 federal survey of nearly 8,600 new immigrants. The survey used an 11-point scale for measuring skin tone.

From those nearly 8,600 participants, she focused on the more than 2,000 who were working and whose skin tone had been recorded during face-to-face interviews