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Comment by arcticfox | Hacker News Reader

Actually, it's not selection bias at all! This result wasn't just drawn out of a 1000-count small college hat, so naive Bayesian priors shouldn't be used here.

As an alum, I specifically went to Olin because I thought it would best help me become a successful entrepreneur. Many people do.

So my priors are that Olin is likely to do this at a higher rate (since Stanford / MIT etc. have entire swathes of the school not interested in entrepreneurship at all); this evidence makes that seem overwhelmingly likely now.

Consider evaluating all the departments of a school and finding out that one of the smallest turns out the highest percentage of high-energy physicists. Selection bias? Nope, just the high-energy physics department.

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>Actually, it's not selection bias at all! [...] As an alum, I specifically went to Olin because I thought it would best help me become a successful entrepreneur. Many people do.

From the link:

>In other words, what we might have perceived as a difference in education quality was really the product of systematic differences in how the considered populations were put together. The groups we considered had a hidden non-random distribution. This is selection bias.

As you just stated, entrepreneur-y students self-select into Olin. The fact the school produces entrepreneurs doesn't have anything to do with the teachers, the curriculum, or the chemicals Olin puts in the drinking water. It's the non-random distribution of students.

It depends what the conclusion in question is, whether selection bias is a factor.

Does Olin produce / graduate founders at ~5 times the rate of Stanford? Yes - no bias.

Is the effect size due to self-selection? Likely at least partially.

If by "partially" you mean "entirely" I agree.

That is like saying, people who self-select to go to the physics department go there only to be with other physics students are and that it, "doesn't have anything to do with the teachers, [or] the curriculum."

What is more likely, is the school does an excellent job affording students the opportunity found successful, venture-backed companies. Similar to the way the Physics professors and curriculum afford physicists the ability to be good at physics.

The fact the article highlights this opportunity for other entrepreneurially minded people, who may want to attend in the future, is exactly what the data in the article is supposed to do.

Stanford also does a good job of helping interested students with those things. It’s just larger and more diverse, and also includes students who want to be judges, literary critics, historians, medical doctors, mathematicians, journalists, school teachers, etc.

If you looked only at the subset of Stanford students with similar interests and backgrounds to Olin’s student population, you’d probably end up with a similar distribution of outcomes.

There's a qualitative difference, though, in being in a place that is full of mostly people who don't share your interests/goals of founding startups (Stanford) versus those who do (Olin). E.g. there's more gay people in Dallas than in San Francisco (owing to population size differences), but the latter is still a much better place to be gay because of the concentration.

Yea, but Stanford has better faculty, better access to startups, and many people value a more well rounded experience.

no, it's called respecting the null hypothesis when making outrageous claims.

I don't agree, I think it's more likely than not that a school specifically designed to foster a particular type of thinking is at least somewhat more effective at it than others. Just like Stanford is likely more effective at developing elite researchers.

I don't think there's nearly enough information to determine that confidently, but we're simply talking about beliefs at this point.

Doubling down on this point, there are undoubtably people who went to Olin not planning to be a founder, who decided to be because they knew someone else who was a good role-model for them.

This is not dissimilar from the old boy network that makes Washington and Lee the single university which most increases your median earning potential. (See https://en.wikipedia.org/wiki/The_Economist_Magazine%27s_Lis... for where I got that from.)

> As you just stated, entrepreneur-y students self-select into Olin.

Well, the best students self-select into Berkeley, Harvard, Stanford, etc.

"it's not selection bias at all"

"I specifically went to Olin because I thought it would best help me become a successful entrepreneur"

choose one

It depends which conclusion is being questioned.

arcticfox is probably referring to the title conclusion "Olin College Produces Founders at Five Time the Rate of Stanford" not being the result of selection bias during the analysis phase (as implied for example in this comment https://news.ycombinator.com/item?id=15184748).

The conclusion "Olin College is more effective at turning people into founders than Stanford" is indeed a far more speculative conclusion due to self-selection.

So would a conclusion that "most sports fans who watch TV watch ESPN" be selection bias?

The FIRST Robotics Team I helped out with has sent three students to Olin so far, with more interested. So not only are these students who self-select, but Olin is getting students who've already had an aggressive, entrepreneurial Engineering project under the belts. Our team has sent students to lots of other Engineering schools, but my sense is that Olin is particularly dense with motivated students.

The incoming class of 2021 http://www.olin.edu/blog/olin-admission/post/welcome-class-2...

"And you love robotics! Which makes so much sense- we are Olin after all!- over half of you participated in competitive robotics in high school."

It is absolutely selection bias. Compare averages by major for each school, not the total population for each school. To compare a college that produces almost exclusively engineering majors to a university that offers everything from constitutional law to communications is absurd.

To say, “it is absolutely selection bias,” infers the professors and curriculum of the school had no effect on the ability of students to become successful, venture-backed entrepreneurs. Which you cannot conclude given the data.

What you have experienced is confirmation-bias. Whereby, you have interpreted evidence to reaffirm your own beliefs. In this case, your belief is, “Olin College cannot be better than MIT, Harvard, Stanford, Yale, and the like because those schools are the best.”

When you allow yourself to succumb to confirmation bias, you close yourself off to the possibility there is a school which prepares students for an entrepreneurial life. Please do not close others off to the same possibility.

I never wrote that MIT, Harvard, Stanford and Yale are better than Olin. What I did say was that you should compare apples to apples, compare average start up rate for majors at Olin to the same majors at MIT, Yale, Stanford and Harvard.

Right now most startups are tech heavy. If you have a school with exclusively engineering and technology majors, you're much more likely to have a higher startup rate then a full university.

To say "it is absolutely selection bias," you have to include Harvard poetry majors in the comparison, which they did. Why so condescending?

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