Regression Discontinuity - Institute for Policy Research

What to do (3)
• Non-parametric approaches
– What are non-parametric approaches?
• Eliminates functional form assumptions
• Performs a series of regressions within an interval, weighing
observations closer to the boundary
• Use local linear regression because it performs better at the
boundaries
– What depends on selecting correct bandwidth?
• Key tradeoff in NP estimates: bias vs precision
– How do you select appropriate bandwidth?
– Ocular/sensitivity tests
– Imbens & Kalyanaraman (2010)
– Cross-validation methods
» “Leave-one-out” method