In Noisy Harmonic Grammar (Boersma and Pater 2016), a stochastic version of Optimality Theory (Prince and Smolensky 1993), the constraints are weighted and the outcomes are probability distributions over GEN, computed by adding a noise factor to the constraint weights at each evaluation. Intuitively, one might expect that constraints bearing zero weights would have zero empirical effect, but this turns out not to be so. First, we show that a constraint with zero weight in NHG continues to affect the probability of candidates that violate it; the effect is either upward or downward, depending on otherfactors. Second, under certain arrangements intended to maintain the principle of harmonic bounding, zero-weighted constraints can force zero probability for candidates that violate them. We suggest what sort of cases linguists should seek in order to test the truth of these predictions, and also point out alternatives we might appeal to if these predictions emerge as false.

This article argues that some ostensible advantages of Optimality Theory with Candidate Chains (OT-CC) over classic OT are actually liabilities. OT-CC correctly predicts that Chamorro umlaut occurs only when trigger and target are adjacent. But OT-CC is incompatible with similar phenomena like Central Venetan metaphony, and attempts to modify OT-CC to produce metaphony impair the theory's handling of umlaut. Classic OT provides a superior approach: constraints grounded in prominence asymmetries produce the umlaut facts, and there is no conflict with analyses of metaphony. This result suggests that despite OT-CC's advancements in treatments of opacity, the theory's machinery remains inadequate in important ways.