In this Q&A in the Providence Business News, Brown University healthcare economist Momotazur Rahman discusses the rates at which participants who use three high-cost services switch between Medicare Advantage and traditional Medicare — and why.

He answers these big questions:

Why do Medicare Advantage users abandon the plans and return to public Medicare precisely when their healthcare costs begin to mount?

Is it time for Congress to update, or replace, the 2003 law meant to prevent flight from private Medicare?

Are there  Medicare Advantage plans with significantly less dissatisfaction and flight?