If you have a business opportunity that has a certain risk and a return potential of $10 the different levels in taxation play a role in the decision whether to invest or not.

In a 30% tax environment your net return is $7 and you would balance that with the risk to decide what to do.

In an extreme scenario, say 60% tax environment, your return would be $4 compared with the same risk of failure.

Obviously if the risk reward balance is not satisfactory you wouldn't invest in the 60% tax environment.

I think Buffett doesn't see tax variation as a deterrent to business because he is analyzing a smaller increase from 30% to 33% or 35% and, as he always uses a margin of safety of 20% to 30% that might buffer any risk return imbalance.

In the macroeconomic context it is clear how tax variations modify economic activity including consumption and investment due to this calculation.

I an Economy with higher tax burdens entrepreneurship and business innovation and investment tend to decrease.