It has been argued that the different ways human resource management is conducted in different countries can be at least partly explained by theories of comparative capitalisms. Earlier work has highlighted much diversity between coordinated market economies, but the liberal markets are commonly assumed to represent a more coherent category. This article scrutinizes the latter assumption more closely by examining differences between the liberal market economies in their approaches to HRM. The authors find that the USA displays greater centralization in human resource management practices, higher turnover rates and less delegation to employees, than in the UK and Australia; this being associated with differences in institutional realities. The study highlights how, under a broad institutional archetype, specific systemic features may exert strong effects on specific HRM practices and challenges assumptions of close institutional coupling in the most advanced economies.