what is the difference between a pigovian tax and a sin tax 
pigovian taxes and sin taxes are quite similar and a specific levy may satisfy both definitions the key difference is that a pigovian tax seeks primarily to minimize negative externalities i e harms to others or society as a whole while sin taxes typically seek to reduce negative internalities i e harms to oneself in the case of cigarettes and alcohol for example there are both potential negative internalities and externalities 