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Causal inference as a blind spot of data scientists

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Re: Causal inference as a blind spot of data scientists

#2
The main reason for not using causal inference is not because data scientists don’t know about the different approaches or can’t imagine something equivalent (a lot of reinvention); forecasting is one of the most common tasks, after all.

The main reason is that they generally work for software companies where it’s easier and less susceptible to analyst influence to implement the suggested change and test it with a Random Control Trial. I remember running an analysis that found that gender was a significant explaining factor for behavior on our site; my boss asked (dismissively): What can we do with that information? If there is an assumption of how things work that doesn’t translate to a product change, that insight isn’t useful; if there is a product intuition, testing the product change itself is key, and there’s no reason to delay that.

There are cases where RCTs are hard to organize (for example, multi-sided platform businesses) of changes that can’t be tested in isolation (major brand changes). Those tend to benefit from the techniques described there——and they have dedicated teams. But this is a classic case of a complicated tool that doesn’t fit most use cases.

Re: Causal inference as a blind spot of data scientists

#3
For a hands on introduction to Causality, I would recommend “Causal Inference in Python” by M. Facure https://amzn.to/46byWnl Well written and to the point.

I also have a series of blog posts on the topic: https://github.com/DataForScience/Causality where I work through Pearls Primer: https://amzn.to/3gsFlkO

Re: Causal inference as a blind spot of data scientists

#4
I've self-learned for a long time in the causal inference space and model evaluation is a concern for me. My biggest concern is falsification of hypotheses. In ML, you have a clear mechanism to check estimation/prediction through holdout approaches. In classical metrics, you have model metrics that can be used to define reasonable rejection regions for hypothesis tests. But causal inference doesn't seem to have this, outside traditional model fit metrics or ML holdout assessment? So the only way a model is deemed acceptable is by prior biases?

If my understanding is right, this means that each model has to be hand-crafted, adding significant technical debt to complex systems, and we can't get ahead of the assessment. And yet, it's probably the only way forward for viable AI governance.

Re: Causal inference as a blind spot of data scientists

#6
I would argue it's more a blind spot of big data, which tends to tacitly imply just doing correlational studies on data that happens to be laying around.

Most data scientists work for companies that don't really want to pay for controlled experiments outside of maybe letting the UI team do A/B tests. Natural experiments can be hard to come by in a business setting. And all of the wild mathematical gyrations that econometricians and political scientists have developed to try to do causal inference from correlational data have a tendency not to be as popular in business because, outside of some special domains such as politics and consumer finance, it can be rather difficult to get away with dressing your emperor in math that nobody can understand instead of actual clothing.

Re: Causal inference as a blind spot of data scientists

#7
post #2

The main reason for not using causal inference is not because data scientists don’t know about the different approaches or can’t imagine something equivalent (a lot of reinvention); forecasting is one of the most common tasks, after all. The main reason is that they generally work for software companies where it’s easier and less susceptible to analyst influence to implement the suggested change and test it with a Ra…

Actually causal inference is also really hard to benchmark. My colleague started an effort to be actually able to reproduce and compare results. Also the algorithms often do not scale too well.

Everytime we wanted to use this for real data it is just a little bit too much effort and the results are not conclusive because it is hard to verify huge graphs. My colleague e.g. wanted to apply it explain risk confounders in investment funds.

I personally also do not like the definition of causality they base it on.

Re: Causal inference as a blind spot of data scientists

#8
Contrasting frequentist statistics and causal inference, and saying the latter often goes beyond the former, makes for a bizarre opening. It's like saying apples have nutritional value, unlike soccer balls. It's like saying trigonometry often goes beyond the scope of calculus.

Re: Causal inference as a blind spot of data scientists

#9
I 100% agree with this blind spot. Most data science coursework avoids the very thing making it a science: the explanation of what change causes what effect. I've been surprised that year after year, programs at so many "Schools of Data Science" keep gliding over this area, perhaps alluding to it in an early stats course if at all.

It's an important part of validating that your data-driven output or decision is actually creating the change you hope for. So many fields either do poor experimentation or none at all, others are prevented from doing the usual "full unrestricted RCT": med and fin svcs and other regulated industries have legal constraints on what they can experiment with; in other cases, data privacy restricts the measures one can take.

I've had many data folks throw up their hands if they can't do a full RCT, and instead look to pre-post with lots of methodological errors. You can guess how many of those projects end up. (No, not every change needs a full test, and some things are easy rollback. But think of how many others would have benefitted from some uncertainty reduction.)

Sure, "LLM everything" and "just gbm it!" and "ok, just need a new feature table and I'm done!" are all important and fun parts of a data science day. But if I can't show that a data driven decision or output makes things better, then it's just noise.

Causal modeling gets us there. It improves the impact of ml models that recognize the power of causal interventions, and it gives us evidence that we are helping (or harming).

It's (IMO) necessary, but of course, not sufficient. Lots of other great things are done by ML eng and data scientists and data eng and the rest, having nothing to do with casual inference... But I keep thinking how much better things get when we apply a causal lens to our work.

(And next on my list would be having more data folks understanding slowly changing dimension tables, but this can wait for another time).

Re: Causal inference as a blind spot of data scientists

#10
post #4

I've self-learned for a long time in the causal inference space and model evaluation is a concern for me. My biggest concern is falsification of hypotheses. In ML, you have a clear mechanism to check estimation/prediction through holdout approaches. In classical metrics, you have model metrics that can be used to define reasonable rejection regions for hypothesis tests. But causal inference doesn't seem to have this,…

To be clear, the mechanism for checking ML doesn't really check ML. There's really little value in a confidence interval conditional on the same experimental conditions that produced the dataset on which the model is trained. I'd often say it's actively harmful, since it's mostly misleading.

Insofar as causal inference has no such 'check', its because there never was any. Casual inference is about dispelling that illusion.

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