I'm curious why you see Sanders' plan as a "clean and elegant" solution to this problem. It is a solution, but it seems likely to introduce some bad incentives at hiring time. For example, if a high school student and a single mother apply for the same job, which one should Amazon hire? Right now, both cost Amazon the same, but under the Sanders plan, hiring the single mother would likely cost a lot more due to the chargeback.

This writeup has some more discussion on the likely negatives of the plan: https://www.cbpp.org/poverty-and-inequality/sanders-khanna-b....