Clustering, Spatial Correlations and Randomization Inference
NBER Working Paper No. 15760
---- Acknowledgements ----
Financial support for this research was generously provided through NSF grant 0820361. We are grateful for comments by participants in the econometrics lunch seminar at Harvard University, and in particular for discussions with Gary Chamberlain. The views expressed herein are those of the authors and do not necessarily reflect the views of the National Bureau of Economic Research.