The father of President Reagan's "supply-side economics" has endorsed both the proposed Utah tax rollback initiatives and Merrill Cook for governor.

Dr. Arthur Laffer, a former Reagan adviser who advocates lowering taxes to stimulate the economy, said, "I heartily endorse Merrill Cook for Utah's governor because Cook espouses the principles of supply-side economics, which I believe could do wonders for Utah's economy."Laffer has agreed to speak at a fund raiser for Cook on Oct. 5 at the Salt Lake Marriott Hotel, where he also plans to outline his support of the tax initiatives.

In an open letter to business leaders, Laffer said large tax increases implemented during the administrations of both former Gov. Scott Matheson and Gov. Norm Bangerter "have resulted in a falling economy amid the economic rise under Reaganomics through the rest of the nation.

"That is because while national tax rates were falling, Utah continued to raise taxes. As a result, Utah has experienced a high rate of bankruptcies, out-migration, overcrowded classrooms with inadequate supplies and poorly maintained highways."

Laffer said the way to turn that around is with a tax cut. "(Cook) knows how to make the tax rollback initiatives work to stimulate the economy and to help properly fund the classrooms where learning really occurs," Laffer said.