Drawing on an actor-centered, historical institutionalist framework, two findings are presented to explain institutional diversity. First, the emergence of cross-class coalitions between capital and labor is necessary for the sustainability of collective solutions towards skill formation. In absence of such coalitions, policy reforms will not lead to institutional change and are bound to be continuously contested and prone to market failure. Second, governments not only have preferences with regard to training policies, but also towards the role organized interests play in training politics. While a collective approach towards vocational training by left governments strengthened the role of unions within industrial relations reforms and contributed to the emergence of cross-class coalitions, the curtailment of union influence in vocational training can be regarded as part of right governments project to decollectivize industrial relations, with the corollary that collective approaches towards apprenticeship ceased to be feasible in the reforms aftermath.