Geographic difference-in-discontinuities

A recent econometric literature has critiqued the use of regression discontinuities where administrative borders serve as ‘cutoff’. Identification in this context is difficult since multiple treatments can change at cut-off and individuals easily sort on either side border. This note extends difference-in-discontinuities framework discussed Grembi et al. (2016) to a geographic setting. paper formalizes identifying assumptions context, which will allow for removal time-invariant sorting similar difference-in-differences methodology.