i***i
发帖数: 99 | 1 最近被问到了，觉得自己回答的很不好，想请教一下怎样回答更好。
背景：marketing consulting firm looking for econometrician/statistical
modeler.
问题：If you run a regression and find the estimated price elasticity is
positive, what will you do?
My answer focused on the cases where postive price elasticities are possible, but I'm afraid he wanted an answer from the practical perspective.
Thanks a lot! |
d*****s
发帖数: 285 | 2 我也碰到过类似的题目，我迟疑了一下，面试官告诉我说他会直接set to 0.
【在 i***i 的大作中提到】
: 最近被问到了，觉得自己回答的很不好，想请教一下怎样回答更好。
: 背景：marketing consulting firm looking for econometrician/statistical
: modeler.
: 问题：If you run a regression and find the estimated price elasticity is
: positive, what will you do?
: My answer focused on the cases where postive price elasticities are possible, but I'm afraid he wanted an answer from the practical perspective.
: Thanks a lot!
|
i***i
发帖数: 99 | 3 为什么set to 0? regression的目的就是要estimate这个参数呀。
【在 d*****s 的大作中提到】
: 我也碰到过类似的题目，我迟疑了一下，面试官告诉我说他会直接set to 0.
|
d*****s
发帖数: 285 | 4 RUN REGRESSION on Price elasticity of demand，通常系数应该是negative, 因为价
格对需求是负影响，所以如果得出来的结果是Positive，一个可行的方案自然是set to
0了。
以上只是我上次面试的经验啊，抛砖引玉，仅供参考。
【在 i***i 的大作中提到】
: 为什么set to 0? regression的目的就是要estimate这个参数呀。
|
d******e
发帖数: 7844 | 5 这种有正负要求的为什么不在run的时候就加上constraint？
to
【在 d*****s 的大作中提到】
: RUN REGRESSION on Price elasticity of demand，通常系数应该是negative, 因为价
: 格对需求是负影响，所以如果得出来的结果是Positive，一个可行的方案自然是set to
: 0了。
: 以上只是我上次面试的经验啊，抛砖引玉，仅供参考。
|
d*****s
发帖数: 285 | 6 不知道啊，我当时面试的时候就跟他说加constraint，他说他们直接set to 0。另外，
constraint怎么加啊？
【在 d******e 的大作中提到】
: 这种有正负要求的为什么不在run的时候就加上constraint？
:
: to
|
i***i
发帖数: 99 | 7 A constraint on a parameter in a regression can normally be added by some
kind of transformation. For example, if you believe beta is positive, then
estimate beta_* instead where beta=exp(beta_*). Then use the Delta method to
obtain the standard erro of beta based on the estimated standard error of
beta_*.
【在 d*****s 的大作中提到】
: 不知道啊，我当时面试的时候就跟他说加constraint，他说他们直接set to 0。另外，
: constraint怎么加啊？
|
o****o
发帖数: 8077 | 8 http://en.wikipedia.org/wiki/Price_elasticity_of_demand
ppl in Econ board should give you a good answer
【在 i***i 的大作中提到】
: 最近被问到了，觉得自己回答的很不好，想请教一下怎样回答更好。
: 背景：marketing consulting firm looking for econometrician/statistical
: modeler.
: 问题：If you run a regression and find the estimated price elasticity is
: positive, what will you do?
: My answer focused on the cases where postive price elasticities are possible, but I'm afraid he wanted an answer from the practical perspective.
: Thanks a lot!
|
i***i
发帖数: 99 | 9 Thanks! I am from Econ, but I wonder whether the interviewer was looking for
a more practical answer. That's why I asked on this board. :)
【在 o****o 的大作中提到】
: http://en.wikipedia.org/wiki/Price_elasticity_of_demand
: ppl in Econ board should give you a good answer
|
l*********s
发帖数: 5409 | 10 why set it to zero? There are significant cases the price elasticity will be
positive. |
o****o
发帖数: 8077 | 11 I don't see any problems in your answer
you approach this issue logically with the follow steps
1. is it possible?
2. in what condition it is possible
3. is the condition applicable to current business case
4. if it is true, how to interpret the result in a way that make business
sense
5. if the possibiity is declined, how to investigate where goes wrong in the
5.1 objective definition
5.2 model set up
5.3 data problem
5.4 code error
.....
so overall your answer is good
for
【在 i***i 的大作中提到】
: Thanks! I am from Econ, but I wonder whether the interviewer was looking for
: a more practical answer. That's why I asked on this board. :)
|
i***i
发帖数: 99 | 12 This is good! Thanks!
the
【在 o****o 的大作中提到】
: I don't see any problems in your answer
: you approach this issue logically with the follow steps
: 1. is it possible?
: 2. in what condition it is possible
: 3. is the condition applicable to current business case
: 4. if it is true, how to interpret the result in a way that make business
: sense
: 5. if the possibiity is declined, how to investigate where goes wrong in the
: 5.1 objective definition
: 5.2 model set up
|
l*********s
发帖数: 5409 | 13 many thanks ^__^
business
the
【在 o****o 的大作中提到】
: I don't see any problems in your answer
: you approach this issue logically with the follow steps
: 1. is it possible?
: 2. in what condition it is possible
: 3. is the condition applicable to current business case
: 4. if it is true, how to interpret the result in a way that make business
: sense
: 5. if the possibiity is declined, how to investigate where goes wrong in the
: 5.1 objective definition
: 5.2 model set up
|
w*****e
发帖数: 806 | 14 牛啊。。再次拜下大牛。。
the
【在 o****o 的大作中提到】
: I don't see any problems in your answer
: you approach this issue logically with the follow steps
: 1. is it possible?
: 2. in what condition it is possible
: 3. is the condition applicable to current business case
: 4. if it is true, how to interpret the result in a way that make business
: sense
: 5. if the possibiity is declined, how to investigate where goes wrong in the
: 5.1 objective definition
: 5.2 model set up
|
