BOSTON – American Indians made significant economic gains during the 1990s, though tribal gambling operations offered no major edge in boosting incomes, according to a Harvard study.

The analysis, released Wednesday, was based on 1990 and 2000 Census numbers from a group that has historically been one of the nation’s poorest. Per capita income rose about one-third for both gaming and nongaming tribes, though it still remained below $10,000 for both groups.

The findings were promising news after decades of struggles for Indians, said Joseph Kalt, a study co-author. He added the similar progress of gaming and nongaming tribes was “striking.”

“It’s turning out gaming isn’t such a huge advantage,” said Kalt, co-director of The Harvard Project on American Indian Economic Development at the John F. Kennedy School of Government, which did the analysis.

Kalt said a bigger factor was expanded “self-determination” in local tribal government, which increased local accountability. The move began in the Nixon administration, but took broader hold during the 1990s.

The gains followed a decade when Indians’ incomes fell and came during a period when federal funding was stagnant.

Even with the progress, American Indians are well behind the overall population in numerous economic measures. At 1990s growth rates, the per capita income of Indians on reservations still won’t match the overall U.S. population for five decades, the study said.

“There’s a big gap to close, but that has been there for decades,” Kalt said. “Now, you’re starting to turn a corner.”

The report measured 15 socio-economic indicators, from unemployment to households receiving public assistance.

The 1990s saw the rise of tribal-run gambling outfits around the country, so Kalt figured the stats would reveal major improvements for tribes involved in gaming, compared to nongaming tribes. He was surprised to find little difference.

For instance, in real per capita income for Indian reservation areas, nongaming areas saw an increase of 30 percent, from $5,678 to $7,365. Gaming area incomes rose 36 percent, from $6,242 to $8,466.

In all Indian areas, the unemployment rate dropped 3 percent (25 percent to 22 percent) in nongaming areas, compared to 4 percent in gaming areas (19 to 15). The percentage of college graduates rose 3 percent for both gaming (13 to 16) and nongaming areas (8 to 11).

Kalt said while tribes in urban areas have been taking advantage of gambling, that has been balanced by the relatively small impact on rural gaming tribes.

“When you’re on a … highway and you’ve got five truck drivers going through per day, you don’t have much of a market,” he said.

Jacqueline Johnson, executive director of the National Congress of American Indians, added that, contrary to public perceptions, a tiny number of tribes count gambling as a major source of revenue.

She said the improvements are best explained by increased tribal self-government, which has expanded since the 1970s as tribes have become better equipped to provide local services, such as police, education and forestry, that used to be run by the federal Bureau of Indian Affairs.

The change shifted accountability from a large federal bureaucracy to local leadership, and led to improved living conditions, Johnson said.

Kalt recalled one tribal leader who told him self-government was “a two-edged sword.”

“I used to be able to blame the Bureau of Indian Affairs,” the man told him. “Now, they blame me.”

The improvements still left Indians well behind the general population. For instance, per capita income on reservations in gaming areas in 2000 was still just 39 percent of the $21,587 per capita income reported in the overall population, which grew 11 percent, from $19,374 in 1990.

Johnson said such numbers are “discouraging, no matter what.” She called for added expansion of self-government and parity with state and local governments in areas like education and health care funding.

“We’re still learning in a lot of areas and our communities are starting to turn around,” she said.