I messed this up the first time. And I apologize to Stefania. Let me see if I can fix it:
The very sharp Stefanie Stantcheva gets trapped into linguistic quicksand, and disappears into the mire. Her Let me disagree with the very sharp Stefanie Stantcheva's statement that "it’s good to be clear... whether you are making an efficiency argument about the reaction to taxes or expressing a social value judgment..." is totally incoherent: so-called "efficiency" arguments rest on a social value judgment—that the existing distribution of wealth corresponds to utility and deservingness, so that reducing the areas of the economy's Harberger triangles would raise societal wellbeing, holding the distribution of wealth constant, while increasing the areas of the economy's Harberger triangles would raise societal wellbeing, holding the distribution of wealth constant. I think that is wrong: the Harberger triangles' changes go to and come from people with different marginal utilities of wealth. Thus whether the total of behavioral responses to balance-preserving fiscal interventions raise or reduce societal wealth, holding the distribution of wealth constant, hinges on who the Harberger triangles go to or come from . If the people they go to and come from do not have the same marginal utility of wealth, then:** "efficiency" can be inefficient.
And to claim the the current distribution of wealth corresponds to utility and deservingness ought to be a lie too big for anyone to swallow. **It's not anything Stefanie Stantcheva would ever say—rather the reverse—but it does implicitly underpin the belief that the sum-of-the-areas-of-the-economy's-Harberger-triangles is meaningful.
I think all these messes are potentially avoided by working in utility space rather than wealth space from teh get-go. But what do I know?
And, otherwise, her twitter thread is totally great: Stefanie Stantcheva: "Optimal Capital Taxation in 7 Tweets: "Simplifying a lot, but here is the core logic...