&quot;below efficiency levels&quot; isn&#x27;t some sort of moral statement, it&#x27;s a mathematical one. It&#x27;s not a question of moving sellers below their break-even point (you&#x27;re correct that would obviously never happen). It&#x27;s about transferring producer surplus to consumer surplus and introducing deadweight loss into the system.<p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Monopsony#Welfare_implications" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Monopsony#Welfare_implications</a> explains it pretty clearly for the example of labor.