Wyoming's real median household income grew at the fastest pace in the nation last year, according to the U.S. Census Bureau.

Real median household income increased 5.4 percent between surveys for 2006 and 2007. At the same time, real median household income in the U.S. increased by only 1.9 percent, according to figures from the Census Bureau's American Community Survey.

Wenlin Liu, senior economist for the state Economic Analysis Division, said even though the American Community Survey imperfectly compares 2007 and 2006 due to how data are collected, the findings are consistent with other state indicators related to income, employment and unemployment.

The driving force behind Wyoming's positive numbers is the energy boom, he added.

Wyoming's median household income in 2007 was $51,731 - higher than the U.S. level of $50,740. The last time Wyoming's median household income was higher than the U.S. was in 1984.

At the same time, the earnings gap between men and women was the highest in nation. Median earnings for women were $28,540 in 2007, compared to $45,310 for men, or a difference of 63 percent.

"The principal reason was the dominance of the mining industry," Liu said.

Liu noted that in third quarter of 2007, 25,000 men were employed in the mining sector, compared to 3,600 women. And even when women are employed in mining, they often work in lower paid occupations like administrative services.

The highest paid sectors, like utilities, mining and construction, are dominated by men, while lower paid sectors like retail trade employ more women.

Wyoming's poverty rate remained steady at 8.7 percent, according to the survey.

"Overall, Wyoming's poverty rate has been declining since 2000," Liu said. "Lower income workers are probably benefiting from the tight labor market."

People are able to find additional jobs if necessary and labor shortages put upward pressure on wages, he noted.

Business Editor Tom Mast can be reached at tom.mast @trib.com, or call 307-266-0574.