Regression-Discontinuity Design - Institute for Policy Research

Non‐parametric Approach
lim
x↓c
E[Y i
| z i
= z c
]− lim
x↑c
E[Y i
| z i
= z c
]
• Where z i is the assignment score, z c is the
cutoff, and Y i are the outcomes.
• Treatment effects estimated by examining the size
of the discontinuity in the conditional expectation of
the outcome given the assignment variable for
observations at the cutoff.
• The limits are often estimated by non-parametric
local linear kernel regression.
• Allows analyst to relax assumptions about functional
form away from the cutoff.