Opportunity costs and the “endowment effect” Underweighting of opportunity costs= endowment effect. * Tax cut= “Gain” or “Less of a loss”? * Credit card surcharge versus cash discount. Sunk costs Sunk cost effect= paying for the right to use a good or service will increase the rate at which the good/service will be used. * Snowstorm ballgame example * Tennis club membership/multipart pricing * Commitment to prior decisions (e.g., Vietnam War)