Sebastián Castillo is a Postdoctoral researcher at the University of Helsinki and the Centre of Excellence in Tax Systems Research (FIT). He is primarily interested in public economics and uses empirical and theoretical tools to study it. His research focuses on income tax evasion, optimal taxation, and the effect of tax evasion on labor decisions. Also, he is studying VAT evasion and firms' behavior in a developing country context. He holds a Ph.D. in Economics from the Pontificia Universidad Católica (PUC) de Chile, and a Master and a Bachelor in Economics from Universidad Alberto Hurtado.