Washington — Iranian-Americans are far more numerous in the United States than census data indicate and are among the most highly educated people in the country, according to research by the Iranian Studies Group, an independent academic organization, at Massachusetts Institute of Technology (MIT).

The group estimates that the actual number of Iranian-Americans may top 691,000 — more than twice the figure of 338,000 cited in the 2000 U.S. census. According to the latest census data available, more than one in four Iranian-Americans holds a master’s or doctoral degree, the highest rate among 67 ethnic groups studied.

With their high level of educational attainment and a median family income 20 percent higher than the national average, Iranian-Americans contribute substantially to the U.S. economy. Through surveys of Fortune 500 companies and other major corporations, the researchers identified more than 50 Iranian-Americans in senior leadership positions at companies with more than…