Consider a labour market monopsonist that faces the labour supply w = 10 + L. Its technology level determines that the marginal revenue product of labour is featured by MRP = 130 - 2L.

a) Write down the marginal cost of labour (MC) function.

b) Calculate employment level and wage rate paid by this monopsonist. How much is the total labour cost?

c) If government imposes a minimum wage at $45, how many workers will be hired? How much is the total labour cost?

d) If government imposes a minimum wage at $80, how many workers will be hired? How much is the total labour cost?

e) If this firm can practice perfect monopsony wage differentiation, i.e., paying each worker a different wage, how many workers will be hired? How much is the total labour cost?