It’s impossible to predict the outcome of a random experiment. Yet that is the task that awaits us as we try to make sense of another Donald Trump era.

The only observation I dare make in these early days is that Trump 2.0 is starting where Trump 1.0 ended – with distortions, convoluted logic, and the related risk of major policy blunders. While that is hardly a brilliant predictive insight, it gives a fair sense of what we are dealing with.

I could point to any number of actions Trump took on his first day back, but his memorandum detailing an “America First Trade Policy” caught my economist’s eye. It touche...