A significant part of policy-making involves matching policy goals with the ideas formulators hold about feasible and desirable mixes of policy means or tools. However, these plans have little reality until they have been ‘implemented’, or put into practice. The process of matching goals and means is part of policy formulation while putting these plans into practice is the subject of policy implementation. Instrument preferences or ‘implementation styles’ develop as a function of a variety of factors, including state capacity and familiarity of policy designers, decision makers, and administrators with specific kinds of tools. These are important determinants of the mix of policy tools found in any issue area or policy sector.