Over-Regulation Leads To Too Much Regulatory Discretion And Whimsy

From The Grumpy Economist "Local Regulation" by John Cochrane:

We talk about "regulation," but the real issue is rules vs. discretion. Regulating by simple clear rules is much better than regulation by discretion, or by rules so complex they amount to discretion. When a zoning inspector can come in after the fact and always find something wrong, it's in invitation to corruption. We are increasingly a country in which "regulation" means that regulators can tell people what to do on a whim, not one in which clear objective rules are imposed.

The ill effects of this sort of over-regulation are hard to measure, so they tend to be forgotten. We talk about tax rates, spending and laws. But how do you quantify the far more important effects of this sort of thing? It's far worse than an explicit tax, or on the books spending. But it just shows up as mysterious lack of business. We can find isolated anectdotes, but how do we add up the effects of regulatory harassment across the whole country?