Xiaoxia is very patient in explaining the details of the proofs. Additionally, she is very accessible outside class, holding office hours twice a week and respond to emails fairly quickly.

a hard-core professor

Arguably one of the worst teachers I've had at UW. Econ 410 is already one of the hardest undergrad econ classes and she added an unnecessary level of difficulty. She did a poor job of explaining how to use STATA, which is very important for the homework. Homework and class in general is also too focused on proofs which are explained poorly.