Microsoft has been making daily copies of the entire CRAN website of R packages since 2014. This archive, named MRAN, allows installing older versions of packages, which is valuable for reproducibility purposes. The 15,000+ R packages on CRAN are incessantly updated. For example, the package tidyverse depends on 109 packages; these packages accumulate 63 updates, just…
Author: Uri Simonsohn
[103] Mediation Analysis is Counterintuitively Invalid
Mediation analysis is very common in behavioral science despite suffering from many invalidating shortcomings. While most of the shortcomings are intuitive [1], this post focuses on a counterintuitive one. It is one of those quirky statistical things that can be fun to think about, so it would merit a blog post even if it were…
[102] R on Steroids: Running WAY faster simulations in R
This post shows how to run simulations (loops) in R that can go 50 times faster than the default approach of running code like: for (k in 1:100) on your laptop. Obviously, a bit of a niche post. There are two steps. Step 1 involves running parallel rather than sequential loops [1]. This step can…
[100] Groundhog 2.0: Further addressing the threat R poses to reproducible research
About a year ago I wrote Colada[95], a post on the threat R poses to reproducible research. The core issue is the 'packages'. When using R, you can run library(some_package) and R can all of a sudden scrape a website, cluster standard errors, maybe even help you levitate. The problem is that packages get updated…
[99] Hyping Fisher: The Most Cited 2019 QJE Paper Relied on an Outdated Stata Default to Conclude Regression p-values Are Inadequate
The paper titled "Channeling Fisher: Randomization Tests and the Statistical Insignificance of Seemingly Significant Experimental Results" (.htm) is currently the most cited 2019 article in the Quarterly Journal of Economics (372 Google cites). It delivers bad news to economists running experiments: their p-values are wrong. To get correct p-values, the article explains, they need to…
[96] Madam Speaker: Are Female Presenters Treated Worse in Econ Seminars?
A recent NBER paper titled "Gender and the Dynamics of Economics Seminars" (.htm) reports analyses of audience questions asked during 462 economics seminars, concluding that “women are asked more questions . . . and the questions asked of women are more likely to be patronizing or hostile . . . suggest[ing] yet another potential explanation…
[95] Groundhog: Addressing The Threat That R Poses To Reproducible Research
R, the free and open source program for statistical computing, poses a substantial threat to the reproducibility of published research. This post explains the problem and introduces a solution. The Problem: Packages R itself has some reproducibility problems (see example in this footnote [1]), but the big problem is its packages: the addon scripts that…
[91] p-hacking fast and slow: Evaluating a forthcoming AER paper deeming some econ literatures less trustworthy
The authors of a forthcoming AER article (.pdf), "Methods Matter: P-Hacking and Publication Bias in Causal Analysis in Economics", painstakingly harvested thousands of test results from 25 economics journals to answer an interesting question: Are studies that use some research designs more trustworthy than others? In this post I will explain why I think their…
[88] The Hot-Hand Artifact for Dummies & Behavioral Scientists
A friend recently asked for my take on the Miller and Sanjurjo's (2018; pdf) debunking of the hot hand fallacy. In that paper, the authors provide a brilliant and surprising observation missed by hundreds of people who had thought about the issue before, including the classic Gilovich, Vallone, & Tverksy (1985 .htm). In this post:…
[80] Interaction Effects Need Interaction Controls
In a recent referee report I argued something I have argued in several reports before: if the effect of interest in a regression is an interaction, the control variables addressing possible confounds should be interactions as well. In this post I explain that argument using as a working example a 2011 QJE paper (.htm) that…