Assume no externalities and the buyers and sellers interact in a
market. Currently we have three buyers who value a good at $40.
There are three possible sellers A, B, C whose marginal costs of
production are $20, $30 and $50. Another seller, D, enters the
market. D's marginal costs of production is $40. What is the change
in Total Surplus caused by D's entry? Do not include the $ sign and
remember to include a negative sign if you...