Suppose a firm has an annual expenses of $170 000 in wages and salaries , $75090 in materials , $60 000 in rental expense , and $5 090 in interest expense on capital . The owner - manager does not choose to pay himself , but he could receive income of $90.090 by working elsewhere . The firm earns revenues of $320.000 per year 41 . What are the annual economic costs for the firm described above ? The discount rate increases $305 000 $310.000 . 5 $400 000 42 . What is the economic profit for the firm described above ? $60 000 $10.000 Loss of $80 000 Loss of $90.000