We are big fans of Illinois Treasurer Michael Frerichs, and were very pleased to see his new report on how CEOs spent the extra money from the Trump tax cut.
The theory and the promise was that this money would trickle down to employees, consumers, and investors, and that it would be used to improve operations and products. The President said at the signing ceremony:

And I’ve had many calls such as that, where people that are entrepreneurs, people in businesses, they’re going out and they’re going to buy, frankly, factories that are closed, abandoned, and now they’re not going to be abandoned any longer. This is having an even bigger impact, faster than I thought.

The corporate tax rate, as you know, will be lowered from 35 to 21 percent. That means that more products will be made in the USA. A lot of things are going to be happening in the USA. We’re going to bring back our companies. They’ve already started coming back. I think they had certain confidence in me and they figured we were going to get this done. But they have already started.

First, here is how citizens wanted it to be spent.

What did they do? Well, we’re not sure.

40 percent of respondents chose not to disclose their plans for their tax savings. Instead of disclosing specific plans or figures, these respondents replied by describing general capital deployment strategies or referring surveyors to previously issued reports with nondescript information on plans for the use of anticipated tax savings. In total, among all S&P 100 companies surveyed, 81 percent either chose not to disclose their plans for any anticipated tax savings or chose not to respond.

They did get some information.

[A]mong the 29 companies that announced and quantified their plans for the use of tax savings, product investments received the largest share (17 percent), followed by investments in jobs (11 percent), workers (7 percent), customers (4 percent) and communities(3 percent). While this provides a degree of clarification as to how companies plan to distribute tax savings, it is important to note that these same respondents did not specify how the majority
of estimated tax savings (58 percent) will be distributed.