ijyliu / ECMA-31330-Project

Econometrics and Machine Learning Group Project
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Why is IV doing so well now? #90

Closed ijyliu closed 3 years ago

ijyliu commented 3 years ago

It seems like IV is now beating everything else by a ton in the sims. This is true in both the non-transformed and the half-transformed case.

This seems to have happened after the run Paul uploaded yesterday. You can see where the tables changed here: https://github.com/ijyliu/ECMA-31330-Project/commit/27c837e75e953764bbe076aab79b7a74ed5703b0

So I think this is the result of including an intercept in the simulations and the IV first stage, or switching from 2SLS by hand to the statsmodels package.

ijyliu commented 3 years ago

Notes:

IV collapses when you bump p up to like 100 or 500, but at this point averaging does well again. So, the ideal environment for PCA is to do the transformation and a large p.

ijyliu commented 3 years ago

Notes:

Estimator probably does better with p roughly equal to N

Ideal empirical setting might be more p and more principal components

With more time, could try to use an optimizer to find precisely ideal conditions for the estimator

paul-opheim commented 3 years ago

I think we've resolved this.

ijyliu commented 3 years ago

Note for isaac to maybe note in like the conclusion:

Ideal empirical setting might be more p and more principal components

With more time, could try to use an optimizer to find precisely ideal conditions for the estimator

ijyliu commented 3 years ago

@marionoro added this to conlusion

image

probably can close this issue now

paul-opheim commented 3 years ago

Hmm I don't think that we should add that. I don't think we need/should mention the ways in which what we did was incomplete.

ijyliu commented 3 years ago

ok I want to hear @nicomarto 's opinion tho

nicomarto commented 3 years ago

Hmm, I would say that instead of that we could say "an interesting extension of this project could be an empirical case where p is large and n small"?

paul-opheim commented 3 years ago

I think that makes sense.

ijyliu commented 3 years ago

ok let me draft something

nicomarto commented 3 years ago

good!

ijyliu commented 3 years ago

image

paul-opheim commented 3 years ago

Looks good to me.

nicomarto commented 3 years ago

Good job Isaac!