Taxes and Trade: When a Number Being "Big" Depends on the Issue

Paul Krugman had an interesting blog post today on the impact of the Republican proposal to cut the corporate income tax. While he rejected the growth claims of the Trump administration, he noted the projections of the Penn-Wharton model that the tax cuts would increase GDP between 0.3 to 0.8 percent by 2027. He described this increase as "basically an invisible effect against background noise." 

This is worth comparing with the projected gains from the Trans-Pacific Partnership (TPP). T...