Yes, there is. If you are suggesting that literally no-one has ever thought: I will compare tax systems between countries...then yes...they have done that. And

Yes, there is. If you are suggesting that literally no-one has ever thought: I will compare tax systems between countries...then yes...they have done that. And yes there are lots of objective measures of progressivity: https://en.wikipedia.org/wiki/Progressive_tax#Measuring_progressivity https://en.wikipedia.org/wiki/Progressive_tax#Measuring_prog... A good, brief, summary is - https://www.washingtonpost.com/news/wonk/wp/2013/04/05/americas-taxes-are-the-most-progressive-in-the-world-its-government-is-among-the-least/ https://www.washingtonpost.com/news/wonk/wp/2013/04/05/ameri... - and there is also this in the Economist which explains the issues around spending in more detail - https://www.economist.com/united-states/2017/11/23/american-taxes-are-unusually-progressive-government-spending-is-not https://www.economist.com/united-states/2017/11/23/american-...