I would like to ask if there is a more precise definition of the Externality Cost tab under the Effects brunch.

Also, where I set the allowance price for CO2 emissions? Under the Externality Cost tab?

Thank you in advance

Sincerely

Have you seen the help page on this variable? It's very brief, but concise:

You could use this variable to set a CO2 price, if you wanted to apply it anywhere the pollutant is emitted, and for it to appear in your social cost-benefit results.

Taylor