# Data Science

## The Causal Representation of Panel Data: A Comment On Xu (2022)

NB: An earlier version of this post critiqued Victor Chernozhukov’s approach to directed a-cyclic graphs and fixed effects, but made some critical errors in interpreting his approach. These errors were entirely mine, and I apologize to Victor for doing so.

## Which Religious Groups Have the Most Sex?

There has been plenty of discussion about declining fertility rates and patterns of marriage among people in the United States following the news that the US birth rate declined to its lowest since the Great Depression.

## An Overview of Data for COVID Analysis

The COVID-19 pandemic has led to a wealth of research studies examining various aspects of the pandemic. In this post, I will discuss some of the available datasets for doing aggregate level analysis, i.

## How to Estimate Models with Measurement Error for our COVID-19 Indices

This tutorial gives an overview of the COVID-19 policy indexes just released by the CoronaNet project of which I am a part and the Oxford Government Response Tracker.

## The Good, the Bad and the Ugly in the CDC's Face Mask Study

While perusing the news, I read eagerly about the CDC’s recent study examining associations between county-level mask mandates and COVID-19 growth rates. This study has already been the subject of angry retorts from the restaurant industry due to the CDC’s claim that restaurant closures reduced COVID-19 spread.

## Why People Are Doubting the AstraZeneca Vaccine Report

In this blog post, I use Gelman and Loken’s garden of forking paths analysis to construct a simulation showing why skepticism of AstraZeneca’s vaccine results is warranted at this early stage.

## A More Realistic P-Value for the Pfizer Vaccine Report

I start with Eric Novik’s excellent blog post on how to calculate the relevant statistics for the vaccine, i.e. vaccine efficacy (VE). This is defined as: $VE = 1 - \frac{p_t}{p_c}$

## Why You Should Be Careful About the MaterniT 21 Test

My wife and I have been faced with a decision in our pregnancies that has always caused me some consternation: should we take the MaterniT 21 test to see if our baby might have Down’s syndrome (trisomy 21) or other genetic abnormalities?

## What Panel Data Is Really All About

We’ve all been in that seminar where the author puts up a slide containing regression coefficients, and buried in the bottom line of the table we can see little Ys and Ns indicating the kind of panel data model employed.

## A Proposed Model for Partial Identification of SARS-CoV2 Infection Rates Given Observed Tests and Cases

For an up to date version of this model, please see our paper at https://osf.io/preprints/socarxiv/jp4wk/.