So the cut that went into effect in '83 was passed in '81, just before a recession hit. So the US seeing an increase in revenue compared to the few years before that where unemployment was up over 8% and gdp dropping, is really more about the economy recovering than tax policy changes.

proven likely true means not proven true. Way to many factors. I personally thing the theory has a sorta merit but is very limited and vague (in the sense of there is no identification of where the exact sweet spot of taxation levels are). For example the punitive measures for not paying taxes at very high levels need to be very severe to curtail such behavior. So five figure owning person or mom and pop shop you give a slap on the wrist. Maybe 10% of owed added. Wealthiest individuals and companies get knocked completely out of their level so like 500% of what was owed.

nor does it justify any cut after 1983.

That was my point on how it is misused.