I agree. Unfortunately it is extremely difficult to measure the effects of any particular regulation. It's a one-off, under very specific historical circumstanc

I agree. Unfortunately it is extremely difficult to measure the effects of any particular regulation. It's a one-off, under very specific historical circumstances and it interacts with a huge number of equally unrepeatable events. I don't envy economists. No double-blind lab trials here. Even if we had Putnams Twin Earth our experiments would probably fail for some weird semantic reason :)