Regression discontinuity rd analysis is a rigorous nonexperimental1 approach that can be used to estimate program impacts in situations in which candidates are selected for treatment based on whether their value for a numeric rating exceeds a designated threshold or cutpoint. Mosek is a commercial interior point solver that needs to be installed separately, while quadprog is a standard r optimization library. It is one of the most credible quasiexperimental research designs for identi. The analysis of the regressiondiscontinuity design in r. The main new features of this upgraded version are as follows. We can select similar control groups using matching or controlling what economists call selection on observables we can use a treated group at a different time as its own control group with fixed effects. We use real data from the carolina abecedarian project to show how an analysis of an rdd can be performed from start to finish. Estimation is accomplished using local linear regression. The function alpha from the package scales allows to adjust the opacity of colors.
Weve been going over ways in which we can use control groups to isolate causal effects. An r package for robust nonparametric inference in regressiondiscontinuity designs. R linear regression regression analysis is a very widely used statistical tool to establish a relationship model between two variables. Rd plots, estimation, inference, and extrapolation with multiple cutoffs and multiple scores. A practical introduction to regression discontinuity. Does a discontinuity occur in the regression at the cutoff point. We describe a major upgrade to the stata and r rdrobust package, which provides a wide array of estimation, inference, and falsification methods for the analysis and interpretation of regression discontinuity designs. We will make use of the tidyverse verb mutate and pipe operators from the magrittr package to create d. Rdestimate supports both sharp and fuzzy rdd utilizing the aer package for 2sls regression under the fuzzy design. The basic idea of regression discontinuity rdd is the following.
The analysis of the regressiondiscontinuity design in r article in journal of educational and behavioral statistics 423 november 2016 with 998 reads how we measure reads. Rddtools is a new r package under development, designed to offer a set of tools to run all the. An application to the study of party advantages in the u. Provides the tools to undertake estimation in regression discontinuity designs. In the rd design, all units have a score, and a treatment is assigned to those units whose value of the score exceeds a. The regressiondiscontinuity rd design is widely used in applied work.