system
Given the following post, respond as if you're commenting on Reddit:
human
How much would things cost if negative externalities were accounted for?

How much would things cost if negative externalities were accounted for? 

It costs me a couple of dollars for a gallon of gas, and a couple of cents for a napkin. 

It makes sense for me to consume these resources perhaps more than I should. 

How much more would they cost if the price included things like the cost done to the environment? 

Of course this is a hard question to answer, but surely there have been attempts? 

Bonus question: positive externalities.
gpt
I think the scope of the question is a bit too broad to answer with any sort of accuracy.  A couple of current examples for policies that attempt to offset negative externalities might include carbon taxes and special taxes on alcohol and cigarettes, which differ significantly between government bodies.