Testing/correcting for heteroskedacity/serial correlation/multicollinearity

Do we have to know this?

The learning outcomes state:

k) Explain the types of heteroskedacity and how heteroskedacity and serial correlation affect statistical inference.

l) Describe multicollinearity, and explain its causes and effects in regression analysis.

It doesn’t really explicitly state that we have to know how to test and correct for them. Taking heteroskedacity as an example, there is a section in the book for ‘4.1.1 The Consequences of Heteroskedacity’. This should cover the LOS as described above. There are then separate sections for testing and correcting, 4.1.2 and 4.1.3 respectively.

I had skipped the testing/correcting but now I’ve come to the EOCs and Question 9B P.380 is asking me to describe in detail how I would formally test for conditional heteroskedacity.

Thoughts? Did I jump the gun? Do I have to go back and learn all that stuff?

Hmmm… having just gone through the Ethics session, my advice to you would be to learn as much as possible. wink

If its in the book then I would say, learn it… who knows what is going to show up on that exam…

Don’t do it mojo. i say you take the risk.

I don’t think there’s a reason not to know it, from my personal opinion. It’s in the CFAI books and not an optional segment, so I think you should know it from their perspective as well.

There’s no point to learn statistics (or any topic, really) if you’re not going to learn what you’re actually doing and if you’re doing it properly (fitting and building a model, testing assumptions, correcting for violated assumptions)…Unless you just want to sound impressive at the holiday party when you use vocabulary words like autoregressive conditional heteroskedasticity or multicollinearity, just hope that no one else knows what they’re talking about either.

I would highly recommend that you a) learn how to detect the problem; b) know what the impacts to the model are if one of the above-mentioned are present; c) how to correct the problem(s)

Yeah it seems it was wishful thinking on my part as the other questions have many more Qs on it and DW tests, etc. Never mind, learnt.

It’s all fair game but (like I just said in another post) quant is not heavily weighted so don’t get too caught up in it. I thought quant was the hardest read in all of L2. Could’ve spent 6 months studying just that topic.