2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/99538We study signed differential posets, a signed version of differential posets. These posets satisfy enumerative identities which are signed analogues of those satisfied by differential posets. Our main motivations are the sign-imbalance identities for partition shapes originally conjectured by Stanley, now proven by Lam, Reifergerste and Sjostrand. We show that these identities result from a signed differential poset structure on Young's lattice, and explain similar identities for Fibonacci shapes.References updated. 20 pagesCombinatorics06A07text