Assume that you had a ticket for a concert that you bought for $50, the maximum price you were willing to pay. If a fellow student offers to buy the ticket for $100 but you decide not to sell, what could explain your decision? a) You expect to receive greater utility from attending the concert than you received from buying the ticket. b) The endowment effect c) The law of diminishing marginal utility d) The income effect from the increase in the price of the ticket from $50 to $100 was greater than the substitution effect