Typically, fair machine learning research focuses on a single decisionmaker and assumes that the underlying population is stationary. However, many of the critical domains motivating this work are characterized by competitive marketplaces with many decisionmakers. Realistically, we might expect only a subset of them to adopt any non-compulsory fairness-conscious policy, a situation that political philosophers call partial compliance. This possibility raises important questions: how does the strategic behavior of decision subjects in partial compliance settings a ect the allocation outcomes? If % of employers were to voluntarily adopt a fairness-promoting intervention, should we expect % progress (in aggregate) towards the bene ts of universal adoption, or will the dynamics of partial compliance wash out the hoped-for bene ts? How might adopting a global (versus local) perspective impact the conclusions of an auditor? In this paper, we propose a simple model of an employment market, leveraging simulation as a tool to explore the impact of both interaction e ects and incentive e ects on outcomes and auditing metrics. Our key ndings are that at equilibrium: (1) partial compliance ( % of employers) can result in far less than proportional ( %) progress towards the full compliance outcomes; (2) the gap is more severe when fair employers match global (vs local) statistics; (3) choices of local vs global statistics can paint dramatically di erent pictures of the performance vis-a-vis fairness desiderata of compliant versus non-compliant employers; and (4) partial compliance to local parity measures can induce extreme segregation.Recently, a more critical thread in algorithmic fairness scholarship has called for a broader, systems-level approach to "fairness", recognizing that algorithmic decisions do not happen in a vacuum [30,28,37,47,21,25,32]. Decisions may have long-term rami cations for individual welfare beyond the snapshot captured at 1