A factory benefits from discharging effluent, q, into a lake. The marginal benefit function is given by 60-2q. The pollution causes damages to two nearby communities. The marginal damages to Community A are 1q. The marginal damages to community B are 2q.
What is the total welfare (i.e., total surplus) at this outcome? (Hint: total benefits of pollution to factory minus total costs of pollution to the communities.)