Critical Reading: Papers from 2011 ACM RecSys and Management Science Introduction Recently, I’ve been trying to understand how recommendation systems affects the diversity of user experience. Before I start my own project, I’d like to see what smart people have done. So I read the entire collection of papers from ACM…

How Bill and Melinda Gates’ favorite book Factfulness will leapfrog your data science practice Motivation So far, data science education focus heavily on data wrangling, hypothesis testing and causal inference. Very rarely do we hear about the preceding step — hypothesis formation. Forming the wrong hypothesis is costly Once you’re set on testing a hypothesis, you can…

What is Structural Estimation? Introduction Structural estimation, the holy grail of applied econometrics, the two words that drive fear into the bravest souls. Nail it as a PhD student, and you’re on your way to a top tenure-track professorship. So what is the magic? Specifically, how can it outperform the usual…

I analyzed 100K papers to find out. Motivation Recently, I took a long break from posting on Medium. The 2nd half of the Public Finance class at Stanford is about structural estimation. These paper easily run up to 100 pages/paper, and are filled with greek letters and lengthy, complex sentences. This…

Case study: who pays for mandated childbirth coverage? In today’s Public Finance III lecture @ Stanford, Professor Petra introduces one of the most widely used causal inference technique: difference-in-differences (diff-in-diff). To make our discussion less dry, she motivates the need for this cool technique in the context of mandated benefits. The Question …

Does unemployment benefit make people lazy? — This week in Public Finance III @ Stanford University, Professor Persson talks about optimal insurance design. This class has 78 lecture slides in total. I will compile them into a breezy, 7-minute read for you. The Danger of Eyeball Data Science Does unemployment benefit make people lazy? If it does, states with higher benefit would have…

In this lecture, Professor Perrson tackles the problem of asymmetric information. We will see two Nobel-winning models, and discuss ways to detect adverse selection. This lecture has 55 slides, and I will condense it into a 7 min read for you. Introduction Imagine you’re running an insurance company. How would you turn a profit? As in any other business, you have to price…