But by using data sets from the United States and United Kingdom that show handedness, test scores and salaries, Goodman determined that lefties have 10 to 12 percent lower annual earnings than righties.

Median annual earnings for male lefties in the U.S. are about $2,500 lower than male righties, and female lefties make about $3,400 less than female righties, Goodman finds.

“Lefties exhibit economically and statistically significant human capital deficits relative to righties, even conditional on infant health and family background,” Goodman writes. “Lefties work in more manually intensive occupations than do righties, further suggesting that their primary labor market disadvantage is cognitive rather than physical.”