Would you agree that the oil depletion allowance was also in the nature of financial assistance then?
Yes it was. It encouraged oil companies to play games with the accounting by vertically integrating. If a company owned the wells, processed the crude oil, and sold gasoline and other products to final consumers, it could control the price it charged its own units for the oil.
This was a bad law and it was good to have it end in 1974. Afterwards many oil companies got rid of their downstream retailers.