Diminishing marginal utility(DMU)is neither necessary nor sufficient for downward sloping demand. Yet upper-division undergraduate and beginning graduate students often presume otherwise. This paper provides two simple counter examples that can be used to help students understand that the Law of...

Engineering models generally find that most consumers are unwilling to adopt energy efficient appliances, even though the financial returns are positive. It is commonly thought that this is either due to market imperfections such as an incomplete credit market, very high intertemporal consumer...