Is there a way to create a synthetic control using pooled cross-sectional data, rather than a panel?
I'm analyzing a staggered reform and, so far, the methods I've found require having a panel: Ben-Michael, Feller & Rothstein 2020 (augsynth), Callaway & Sant'Anna 2019 (did), Xu 2017 (gsynth), and potentially also Robbins, Saunders, & Kilmer 2017 (microsynth).