We have multiple people review each application (except the very good/very bad ones) and we look at the cases where the assessments are very different.
Some of the best companies have the most disagreement, which is why we have implemented our "strong yes" policy--if any single partner wants to fund a company, we fund it. It's much more important to our returns that we fund the next Airbnb than if we mistakenly fund one more bad company.
This is a really uninformative answer. Every peer reviewed conference/journal also does this. The NIPS study was special because they did more. They ran a controlled experiment to determine the exact variance in acceptance rates and then published the results. The GP was asking you to repeat the NIPS experiment.
They're in different business. NIPS needs to minimise the amount of really bad papers they accept. YC needs to maximise the amount of really good companies they fund.
Some of the best companies have the most disagreement, which is why we have implemented our "strong yes" policy--if any single partner wants to fund a company, we fund it. It's much more important to our returns that we fund the next Airbnb than if we mistakenly fund one more bad company.