Frankly, no. The issue is a falling share of productive growth going to the not-richest. That is the problem, not the "size of the pie," as it were. In this se

Frankly, no. The issue is a falling share of productive growth going to the not-richest. That is the problem, not the "size of the pie," as it were. In this sense, "incentivizing wealthy into investing it productively" is nothing more than "attempting to con the wealthy into giving up a portion of their share." The alternatives are that nothing changes, or that the wealthy receive an even greater share of growth going forward. But those are prima facie counter to the goal, if you take the findings of the OP to be concerning. In any case, the wealthy are not going to fall for it. They want to maintain or expand their holdings and influence. If you're okay with that - essentially, if you subscribe to trickle-down economics, however misguided that may be - then I supposed that's fine. But either way, we have to be clear what the goal is, and who is going to be helped and and who is going to be hurt by achieving it.