Oh, I have got to see the economic model that predicts that a large principal placed into competently chosen low-risk investments will yield an annual return of only 1.37%*. My bank pays almost double that rate on my checking account.
An overestimate, acutally, since it presumes that you need $100,000/year forever and ever, amen.
You need to remember to include the long term effects of inflation. For example, (the math may be slightly off, because this is a back of hte envelope calculation, but hte point remains):
If one assumes a long term 3.5% inflation rate, $7.3 million in 2037 dollars is only $2.2 million in today's terms. This means that the implied real rate of return on the investments is about 4.6%. Slightly conservative, but not unrealistic.