Table 1.

Joint distribution of counterfactular mediator and outcome

		Y(Z = 0, D(0)), Y(Z = 1, D(1))
		(0, 0)	(0, 1)	(1, 1)	(1, 0)
	(0, 0)	π11	π12	π13	π14	π1+
D(Z = 0), D(Z = 1)	(0, 1)	π21	π22	π23	π24	π2+
	(1, 1)	π31	π32	π33	π34	π3+
	(1, 0)	π41	π42	π43	π44	π4+
		π+1	π+2	π+3	π+4	1