In the last three decades, public tasks have been shifted from central government to a proliferated periphery of autonomous agencies. According to the New Public Management (NPM) doctrine, organizational autonomy would induce these agencies to develop a more private sector-like management, to be more customer-oriented, and to be more accountable for results. Although many governments of most OECD countries continue(d) to change the structure of their public sector fundamentally, following NPM and post-NPM recipes, little was known of the effect of increased autonomy. More precisely, there was a lack of theoretical modelling, appropriate methodologies and empirical evidence about the effects of organizational autonomy. This research addressed this gap by testing the effects of organizational autonomy on (1) the organizational capacity, (2) the managerial and policy processes, and (3) the accountabilities of public sector organizations. These have been identified as necessary preconditions for a better organizational performance.