People who moved into North Dakota in the past decade brought home about $850 million less than those who left the state, an analysis of tax records shows.

But the trend seems to be slowing, with net income loss at its lowest level since 1997, according to a report from the state Data Center.

"We're actually seeing a downward trend, so that's positive news," said Richard Rathge, the center's director.

"However, we have to recognize the positive news and still recognize the serious consequences that we deal with in our state," Rathge said.

The center's report is drawn from federal tax returns filed from 1993 to 2003. They show that North Dakotans who left the state had taxable incomes worth about $5.3 billion; people who moved into the state earned about $4.4 billion.

The total net income loss was pegged at $851 million. The biggest losses were in Grand Forks and Ward counties, which each lost $50 million or more, the Data Center report said.

Grand Forks County's losses during the decade - estimated at $234 million - owed mostly to the 1997 Red River flood and the disbanding of an Air Force missile wing, Rathge said.

"Grand Forks was hit by a number of events that they're just now coming out of," he said. In Ward County, a slower overall loss of residents apparently was to blame, Rathge said.

He said the figures show the significant economic effects of North Dakota's much-discussed population drain.

"Oftentimes when we talk about population loss in the state, people for whatever reason don't pay a lot of attention," Rathge said.

Only two counties gained taxable income from migration: Burleigh County, where employment is driven by state government, and Bottineau County, which has been helped by federal grants and economic development initiatives, Rathge said.

North Dakota's personal income loss due to migration peaked in 2001 and dropped in each of the next two years, the Data Center report said.

That fits with state data that shows North Dakotans reported income growth of about 42 percent between 1994 and 2002, said Kathryn Strombeck, a state Tax Department researcher.

"The fact that you're doubling the rate of inflation is certainly good news," she said.

Strombeck also said the income loss attributed to migrating residents may not give a complete account of North Dakotans' earning power.

The IRS determined whether a taxpayer had moved by plotting where that person's tax return was filed, which may not work well in a state where older residents head south for the winter, Strombeck said.

"When you have a North Dakotan filing one April from North Dakota and the next April from Arizona, they are deemed an outmigrant," she said.

Rathge acknowledged some limitations in the IRS data, but said the overall numbers were large enough to give an accurate reflection of North Dakotans' fortunes.

"The trends are indeed telling us that we still have important concerns in migration in our state, and those concerns do translate into tax dollars," he said.

(On the Net: State Data Center: http://www.ndsu.nodak.edu/sdc.)