Frank likes to play his stereo loudly which gives him marginal benefits per hour of
MBF = 30 - 2H
where H is hours per week. Mike, Frank's neighbor, doesn't like stereo noise and has a willingness to pay for quietness (marginal benefit of stereo noise avoided, Q = - H)
MBM = 20 - 1.5Q
What is the total gain in Mike's welfare at H* compared to the maximum playing time of H =15 hours?
With MBF=30-2H and MBM=20-1.5Q, the equilibrium H* is given by:
MBF=MBM
30-2H*=20-1.5Q
30-2H*=20-1.5*(-H*)
30-2H*=20+1.5H*
3.5H*=10
H*=2.857143
MBM=20-1.5*(-2.857143)=24.28571
When H=15,
MBM=20-1.5Q
=20-1.5*(-15)
=20+22.5
=42.5
Thus, total gain in welfare at H* compared to maximum playing time of H=15 is:
=2.857143*(42.5-24.28571) + (1/2)*(42.5-24.28571)*(15-2.857143)
=162.6276
Frank likes to play his stereo loudly which gives him marginal benefits per hour of MBF...