NO.PZ2020011303000104
问题如下：
What is the ratings momentum effect? Why is it relevant to determining rating transition matrices over periods longer than one year?
选项：
解释：
The ratings momentum effect is that if a bond is downgraded (upgraded) in one year, it is more likely to be downgraded (upgraded) the next year. This means that rating transition matrices in successive years are not statistically independent.
请问这个知识点在基础班哪里有讲到
