Welcome to my personal blog where I post mostly notes about programming in R or Stata. Enjoy!

RATest. A Randomization Tests package is available on CRAN
This blog post introduces the RATest package we released a while back on CRAN with my colleague and good friend Mauricio OlivaresGonzalez. The package contains a collection of randomization tests, data sets and examples. The current version focuses on two testing problems and their implementation in empirical work, mostly related to economics. First, it facilitates the empirical researcher to test for particular hypotheses, such as comparisons of means, medians, and variances from k populations using robust permutation tests, which asymptotic validity holds under very weak assumptions, while retaining the exact rejection probability in finite samples when the underlying distributions are identical. Second, it implements Canay and Kamat (2017) permutation test for testing the continuity assumption of the baseline covariates in the sharp regression discontinuity design (RDD).

A Simple Spatial Equilibrium Model with Tidycensus
The Spatial Equilibrium concept is well known to urban economists. In a nutshell, it states that in equilibrium there are no rents to be gained by changing locations. Ed Glaeser begins Chapter 2 of his book: “Cities, Agglomeration, and Spatial Equilibrium” with the well known AlonsoMuthMills model. In this post, I want to summarize it briefly following Ed Glaeser presentation and reproduce his 2.1. and 2.2. figures. This is the perfect excuse to play around with the “tidycensus” package.

Mapping Racial Segregation in Chicago
This spring break I was reading a couple of papers about segregation in the US (Cutler and Galeser 1997 and Cutler et al 1999). A paragraph on Cutler et al (1999) caught my attention: “Chicago was the most segregated city in 1890, the fourth most segregated city in 1940, the most segregated MSA in 1970, and the fourth most segregated MSA in 1990”. As I was reading this I kept thinking on mapping out Chicago with more recent census data.

An Introduction to Spatial Econometrics in R
This tutorial was prepared for the Ninth Annual Midwest Graduate Student Summit on Applied Economics, Regional, and Urban Studies (AERUS) on April 23rd24th, 2016 at the University of Illinois at Urbana Champaign.

Mean and Quantile Regression using Mosek
Many of the problems we encounter in Econometrics can be formulated as a linear or a quadratic problem. In this post, I want to approach two traditional problems: Quantile Regression and Ordinary Least Squares as convex problems and how to implement them in R using the package RMosek.