CME强化课讲义P22中，有关Credit premium有两条不太好理解：
A steep yield curve predicts both a high term premium and a high credit premium.
credit premium虽然是没预期到的补偿，但也毕竟是因为信用问题所给予的补偿吧？经济越好，为何反而越大呢？
The increase in loan defaults reduces the expected return on corporate bonds. Hence, the credit premium should increase less.
同样，违约上升，credit premium为何会下降呢？
看了一些相关的回答，但还是不太理解，请帮忙详细解答下，谢谢。
