WASHINGTON — A wave of optimism has swept over American business leaders, and it is beginning to translate into the sort of investment in new plants, equipment and factory upgrades that bolsters economic growth, spurs job creation — and may finally raise wages significantly.

While business leaders are eager for the tax cuts that take effect this year, the newfound confidence was initially inspired by the Trump administration’s regulatory pullback, not so much because deregulation is saving companies money but because the administration has instilled a faith in business executives that new regulations are not coming.

“It’s an overall sense that you’re not going to face any new regulatory fights,” said Granger MacDonald, a home builder in Kerrville, Tex. “We’re not spending more, which is the main thing. We’re not seeing any savings, but we’re not seeing any increases.”

The applause from top executives has been largely reserved for the administration’s economic policy agenda. Many chief executives have been publicly critical of President Trump’s approach to social and cultural issues, including his response to a white nationalist march over the summer in Charlottesville, Va., that turned deadly and his decision to withdraw from the Paris climate accord. Two of the business advisory councils that Mr. Trump assembled in the nascent days of his presidency disbanded after executives grew concerned about his public remarks on the violence in Charlottesville.