Tuesday, February 14, 2017

Blast from football past

I stumbled across this NYT article from 2010 about the great David Romer's sweet paper on NFL teams punting too much on fourth down. Good times. I was an RA on that original paper along with several others.

Thursday, February 2, 2017

Trump voters & excess mortality

A year ago, Jeff Guo ran a nice study for WaPo's Wonkblog where he looked at county-level data on primary vote shares for Donald Trump (Y) partially explained by the mortality rate among white non-Hispanics aged 40-64 (X).  His Stata output was included in this tweet.  

Although he didn't look at opioid mortality specifically, that's been the undercurrent since Case and Deaton's study hit in Fall 2015.  On a wry note, make sure to read Ellen Meara and Jon Skinner in the same issue, who discuss the eery parallel (which isn't a perfect one) to Russia.

Thursday, January 26, 2017

DACA safe for now

The LA Times reported on Monday that for now, USCIS appears not to have changed protocols for DACA applications. In his ABC news interview this week, the President indicated that a policy review was coming within 4 weeks, but that “Where you have great people that are here that have done a good job, they should be far less worried,” according to Breitbart.

DACA is available only to a particular set of birth cohorts of unauthorized immigrants who arrived young and who are either in school or have a high school degree or GED (or who have served in the military). My work with Francesc Ortega suggests that unauthorized immigrants with a much broader set of characteristics appear to contribute to our nation's economic well-being. The apparent near-term focus on border security and criminal activity among unauthorized populations seems to recognize this.

Fortune has published a brief article discussing some estimates of the economic impact of DACA.

Wednesday, January 25, 2017

Self-reported citizenship and voting

The topic of unauthorized immigrants arose in yesterday's White House press conference, in a manner I hadn't heard about before: voter fraud. But apparently these issues have been in the news at least since November, as this WaPo article reveals.

At the heart of part of the debate appears to be a dispute over interpreting results from the Cooperative Congressional Election Studies (CCES), a unique large-scale panel survey of over 20,000 respondents in which (some) self-reports are linked to official voter records.

Several researchers from Old Dominion and George Mason published this 2014 study in which they argue: "The proportion of non- citizens who voted [in the 2008 presidential election] was less than fifteen percent, but significantly greater than zero. Similarly in 2010 we found that more than three percent of non-citizens reported voting."

The PI of the panel study itself and coauthors published a relatively brief rebuttal in 2015, in which they highlight the dangers of scaling up rare frequencies of results that are subject to measurement error. They think (and demonstrate) that "measured" noncitizens who voted just answered the survey question incorrectly. To me, the most convincing look at this was in their Table 2, where none of the people who reported being noncitizens in both the 2010 and 2012 waves of the panel had voted:


Another route to go would be to impute documented status in the survey using other characteristics, such as is done in Census surveys by Jeff Passel and colleagues at Pew and Rob and Bob Warren at the Center for Migration Studies.

Wednesday, January 18, 2017

Income mobility at U.S. colleges

TheUpshot at the New York Times published an interactive feature on income mobility at U.S. colleges. Here is the report card for Mills College in Oakland. The data come from The Equality of Opportunity Project, with PI's Raj Chetty, John Friedman, and Nathaniel Hendren.

Tuesday, May 10, 2016

Baseball, final exams, and omitted variables

Here are some fun graphics I put on the final exam this year. One of the fundamental problems in social science inference is that we observe inputs and outcomes without necessarily seeing all relevant variables, and it's difficult to say much about which X's are causing Y.

Here's a look at annual payroll and regular season wins in Major League Baseball between 2007 and 2015, courtesy of MLB.com and the USA Today payroll database.
It's definitely a cloud, but OLS finds an upward sloping line. Now take a look at two randomly selected teams, the Oakland Athletics and San Francisco Giants just for kicks:
There's not much of a clear pattern here at all, in either case. If there really were an upward sloping causal relationship between wins and payroll, you'd also expect to see it here within a team's history over time. But check out the LA Dodgers, whose owner experienced a messy, costly divorce, filed for bankruptcy, and finally sold the team before the 2012 season:
This is seriously fun stuff, because the natural experiment here, namely the essentially forced sale of the Dodgers to cover the enormous costs of a shattered marriage, revealed what looks like a pretty clear upward-sloping relationship between payroll and wins. Even 2015, which was a reduction in both, fits the pattern.

Thursday, February 4, 2016

CDC-totallers

Based on little research and an extreme approach to risk management, the CDC now recommends "that women who are pregnant or might be pregnant not drink alcohol at all." The Times writeup is here. Emily Oster, whose excellent book includes a chapter on this issue, has weighed in: