Essays on policy diffusion

This thesis consists of three essays on policy diffusion which looks at the conditional diffusion of policies based on domestic political factors. It attempts to shed light on how different domestic political factors affect policy diffusion among independent but interrelated actors such as governments. To start, I argue that understanding the effects of unit heterogeneity or more specifically domestic political factors is essential for the understanding of the policy diffusion process. I speculate that this domestic factors’ conditionality is less developed in the literature, for example in contrast to network conditionality, and needs more studies. In three chapters, I look at one theoretical approach using Agent-Based Modelling (ABM) to analyse the effects of domestic politics on the diffusion process, and then it provides two empirical examples in Environmental Spending and Tax Rates Competition. In the first paper/chapter "Domestic and International Determinants of Policy Diffusion: An Agent-Based Approach", using ABM simulation I show how differences in domestic politics or actors’ and voters’ preferences can affect the process of diffusion throughout the whole network of diffusion. This paper focuses on polarisation in voter preferences and conflict between political agents as an example of domestic political factors and shows how changes in such factors can lead to different diffusion macro patterns and characteristics. In the second paper/chapter “Conditional Political Determinants of Environmental Spending Diffusion” I look at the conditional responsiveness of different European states based on their government’s ideological tendencies. I show that such ideological tendencies can affect the diffusion process and the responsiveness of governments towards international stimuli. I argue that in a polarised policy area such as environmental spending different actors fit the roles of leaders or followers depending on the cots and expectations, which will affect their responsiveness to changes in other jurisdictions. In the third paper/chapter “Political Determinants of International Tax Rates’ Diffusion in Europe” I look at diffusion conditionality when alternative and related policy choices exist. I show that domestic preferences can translate into different responses in different alternative policy areas and spatial effects can conditionally spill over from one policy area into another policy area depending on actor’s preferences. Looking at corporate and personal income tax rates as related areas, this third paper finds evidence that links different level of domestic conditionality to the level of international determination in different policy areas, provides evidence that competition or diffusion pressure can spill over from one area to another. I propose that ABM as a theoretical tool, better use of econometrics tools and a more understanding of domestic politics can add to our understanding of policy diffusion process.