It is under no such assumption! If you have sufficient wealth you will leave something even if you die early, by virtue of already having the wealth.
If it’s easier, think of it as the child guarding the parent’s money and deciding whether to place a hedging bet on their parent’s death or not—using said parent’s money. Using the same Kelly formula we’ll find there is some parental wealth at which it pays more to let it compound instead of using it to pay for premia.
It is under no such assumption! If you have sufficient wealth you will leave something even if you die early, by virtue of already having the wealth.
If it’s easier, think of it as the child guarding the parent’s money and deciding whether to place a hedging bet on their parent’s death or not—using said parent’s money. Using the same Kelly formula we’ll find there is some parental wealth at which it pays more to let it compound instead of using it to pay for premia.