The allowance is the will of mj. nothing else
OK, for accuracy sake, here is the relevant article from MJ Trust.
I did not upload the all pages, but they can be found here: http://www.megaupload.com/?d=1L23Z7JN
In essence, 40% of Estate's net earnings go to Katherine's trust. Then, the Trustee has the sole discretion as to how much of that is needed for Katherine's care, support, maintenance, comfort and well-being.. Given the Estate is still on probate, the decisions have to go through the court.
From the article above, I understand that the deal was made to reduce the debt. Considering that the Koreans was sitting in the bushes trying to get their hands on any money coming towards Katherine from the Estate, I believe this loan is a smart move on Estate's part, because at the end that still obliged to ensure Katherine's care, support, maintenance, comfort and well-being.. Simply speaking, if Koreans get Katherine's money from allowance, Estate still obliged to take care of Katherine and ensure all of the above. Because this was Michael's wish.
