我现在有几个考试复习题不回答，也不确定正确答案，请这方面的牛人帮帮忙。谢谢您了！！（鞠躬）
1，if you are intereted in finding the likelihood that a firm will default, what regression technique would you use and why?
2,  how do you test for whether a difference in functional form exists? For example, the problems involving structural shifts, the test used to determine if the model with a structural shift was superior to a less restrictive model. Describe the test and give the lofic for why the test is appropriate.
3,  It is year-end 2012. Your objective is to figure out the association between quantity X and quantity Y which will be used as an input for a simulation. Explain in clear, step-by-step, non-technical detail how you will go about achieving this objective.
4, Explain, with detail examples, the challenges associated with estimating a matrix of associations between pairs of variables for use with simulation work.