Editorial

In this editorial, we summarize and comment on the papers published in Issue 9.3. The first paper is entitled 'The Magnitude and Distance Decay of Trade in Goods and Services: New Evidence for European Countries', by Martin J. Burger, Mark J. P. M. Thissen, Frank G. Van Oort and Dario Diodato. Second, we have the paper by Linda Marie Gerkman and Niklas Ahlgren entitled 'Practical Proposals for Specifying k-Nearest Neighbours Weights Matrices'. The third paper is 'Analytical and Empirical Comparison of Policy-Relevant Key Sector Measures' by Umed Temurshoev and Jan Oosterhaven. Fourth, we have the paper entitled 'Tax Competition with Heterogeneous Firms' by Richard E. Baldwin and Toshihiro Okubo. The final paper is by Félix Modrego, Philip McCann, William E. Foster, and M. Rose Olfert entitled'Regional Market Potential and the Number and Size of Firms: Observations and Evidence from Chile'.