Even the CEO of a major American corporation doesn't necessarily know what he's talking about

This is why we need a diligent news sector. 

AT&T Inc. Chief Executive Randall Stephenson also spoke positively of the economic benefits of a Trump presidency Tuesday....He expressed hope that “a more moderate approach to some of these regulations is in the making under a Trump administration.” Mr. Stephenson said the U.S. is the “highest tax country in the developed world” and that capital investment, as a percentage of gross domestic product, is at its lowest level since World War II.

 From a story in the Wall Street Journal, referenced here.

The reality is not very hard to discover; a quick look at the national income and product data at FRED will show you what reality is.  Or you can look at this hand little chart:

Yep.  Clearly GPDI in the range of 17% is less than at any itme since World War II.  If by World War II you mean the 1990s.