When we use the binomial tree to price the American put, we should compare the discounted value from last nodes and the intrinsic value at each node.
But I confuse that, discounted value from last nodes is the value of European put at this node, and the value of European put is always greater than its intrinsic value, how does it occur the intrinsic value is greater than discounted value?
For the statement the value of European put is always greater than its intrinsic value,
I get from the book Problems and Solutions in Mathematical Finance Equity Derivatives. Volume 2
page 74