If the tax is $500 on an income of $2,500, the income tax rate is

Why must normal profits be counted as a cost, according to economists?

Please provide the best answer for the statement.

Students in a class are assigned to groups to work on a project. A grade will be given for each project, and everyone in the group will receive that grade. For the members of a particular group, the grade is a

A. beneficial externality. B. public good. C. detrimental externality. D. moral hazard.