ST. PAUL — Tom Stinson, the Minnesota state economist whose budget forecasts have shaped tax and spending decisions at the state Capitol for nearly three decades, announced Monday he is retiring.

With 26 years on the job, Stinson, 70, is the longest-serving state economist since the position was created in 1975. While little known to the public, Stinson’s deadpan pronouncements about the peaks and valleys of the Minnesota economy carried great influence with a succession of governors and state lawmakers as they crafted new state budgets.

“He has made this job an institution,” said Jim Schowalter, the Minnesota Management and Budget commissioner. “He has made this position something that we count on as integral to the financial management of the state’s affairs.”

Succeeding Stinson in the job will be Laura Kalambokidis, also, like Stinson, a professor of applied economics at the University of Minnesota. He said he would continue to teach and research, but said the state’s stabilizing economic circumstances after the recession made it a good time for him to leave.

“The state is in better financial shape, the economy is in better shape than it’s been for quite a few years,” Stinson said.

Kalambokidis has served on a handful of Minnesota tax and budget commissions and also worked as a tax analyst for the U.S. Department of Treasury. She will start in July. Schowalter said Stinson would stay on past her start date to ease the transition.

A native of Washington state, Stinson moved to Minnesota in the 1970s. He is not related to Minnesota’s better-known Tommy Stinson, one-time bassist for the famed Minneapolis rock band The Replacements. As state economist, Stinson served five Minnesota governors starting with the late Rudy Perpich.

The principal duty of the state economist is to lead the preparation of a twice-yearly economic forecast that makes detailed predictions about future state tax revenues against anticipated demands for the services that state government provides. State, regional and national economic circumstances all factor into the forecasts, which provide a starting point for the budget decisions made by the governor and lawmakers.

Minnesota’s economy has a long history of outperforming both its regional neighbors and the nation as a whole, producing lower jobless rates and higher standards of living. Stinson said he believes the state’s fundamental strength is the quality of its workforce, and said his main concern as he looks to the future is a decline in high school graduation rates.

“They’re not at the level they need to be,” Stinson said. “That means in the long term we’re diluting the quality of our workforce. That’s really the big challenge the state has looking out 10 years, 20 years, 30 years.”