I have recently read some pieces suggesting that regression discontinuity designs could be the best statistical approach for causal inference stemming from non-randomized studies (eg 1 and 2).
However, as far as I am aware, the strongest claim for accuracy and validity has been made so far for propensity score matching (and possibly inverse probability of treatment weighting) (eg 3)
Thus, what is the comparative accuracy and validity of regression discontinuity vs propensity score matching?