The valuation of bundles is not gain-loss context dependent. H. K. Chung,1* A. Tymula,3 and P.W. Glimcher2. *Correspondence at: hkc278@nyu.edu of Psychology, 2Center for Neural Science, New York University; 3 School of Economics, University of Sydney. Results – Gain-loss reference for decision under uncertainty. Gain ∆U/ ∆X ↓ Diminishing MU Gain (α1-1) 0.4 0.2 0 -0.2 -0.4 -0.6 Loss (1-α2) * * Drinks Snacks Gain: 24+6=30 Loss : 20+24+24+6=74 Total: 30*2+74*2=208 Loss α2 =0.8979 Methods – Certainty Loss Drinks Snacks Parametric analysis - aggregate level N=43 N=22 1 2 3 4 7 Marginal utility 8 Drinks Gain: 32+6=38 Loss : 30+32+30+6=98 Total: 136 𝜌1 𝜌1 1/𝜌1 U (X1,X2)=[β1X1 +(1- β1)X2 ] 𝜌2 𝜌2 1/𝜌2 U (X1,X2)= - [β2|X1| +(1- β2)|X2| ] * Drinks Snacks 0.3 0.2 Prospect theory -4 N=13 It works for decision under uncertainty. N=4 -5 -1 -0.8 MU↓ -0.6 -0.4 -0.2 0 Gain (α1-1) 0.2 0.4 MU↑ 0.6 Non-parametric analysis N=43 Loss (1-𝜌2Median) Gain 0.4 Gain 0.2 Loss 1 0 -0.2 β -0.4 0.5 0 Diminishing MRS Diminishing MRS Gain 0.2 Loss 1 0 -0.2 β 0.5 -0.4 0 -0.6 Prospect theory 0.9 N=5 N=2 Loss -0.1 -1.1 -2.1 -3.1 -4.1 Prospect theory -5.1 -6.1 Loss -7.1 N=26 -1.5 Experimental procedure Endowment * 0.4 -3 Gain (𝜌1Median-1) Gain Comprehension questions 0.5 -2 Loss (1-𝜌2) -0.6 Gain 6 0.6 Loss -1 Parametric analysis - individual level Drinks 5 Gain Coefficient of variation (CV)= SD/EV. 0 0.4 Diminishing MRS Prospect theory N=39 Gain (𝜌1-1) MRSx: MUX ↓ MUY ↑ N=43 r=0.881* for α1s r=0.808∗ for α2s 2 MU↓ Loss (1-𝜌2) MU↑ Snacks Increasing MRS ? MRSx: MUX ↑ MUY ↓ 1 * Non-parametric analysis Results – No gain-loss reference for decision under certainty. However, dose prospect theory also hold for choices amongst riskless bundles of goods ? X MUX Y MUY * -1.2 Prospect theory argues that the gain-loss reference is important for decision-making under risky conditions . Marginal rate of substitution : Loss (1-α2Median) Goods Introduction – Bundle and Indifference curve 8 7 6 5 4 3 2 1 Increasing MU Marginal utility Utility ΔU Marginal Utility: ΔX U(X) = Xα1 for gains U(X) = - |X|α2 for losses Snacks Loss Utility Increasing MU Diminishing MU α1 =0.4612 Gain (α1Median-1) 0.4 0.2 0 -0.2 -0.4 -0.6 MU↑ Gain Outcome ∆U/ ∆X ↑ N=39 MU↓ Kahneman and Tversky (1979) proposed gain-loss asymmetric utility function to explain it. N=43 Parametric analysis - individual level Proportion Choose Risk (Higher CV) option Parametric analysis - aggregate level Marginal utility Previous study found that risk preference is gain-loss context dependent . Methods – Uncertainty Loss (1- α2) Introduction – Prospect theory Marginal utility 1Department 459.02 SS42 -1 N=6 -0.5 MU↓ 0 0.5 1 Gain (𝜌1-1) 1.5 MU↑ 2 2.5 It doesn’t work for decision under certainty. Tasks Practice rounds Lottery blocks (Gain/Loss) Bundle blocks (Gain/Loss) Conclusions and Future plan • Prospect theory holds in the lottery ─ gain-loss reference is important for decision-making under uncertainty. • However, there is no gain-loss reference for choice of riskless bundles . • The marginal utility of each good in a bundle was diminishing not only in the gain domain, but also in the loss domain. • We need both brain data and a more general model that will explain gain-loss asymmetric valuation for lottery and the mechanism of the disappearance of reference for the decisions over riskless bundles. Reference: Kahneman, D., and Tversky, A. (1979). Prospect theory: An analysis of decision under risk. Econometrica, 47(2), 263-291. Varian, H.R. (1992). Microeconomic Analysis (3rd Edition). New York, NY: W. W. Norton & Company. Fixed Probe option option (5,3);(6,3);(7,3);(8,3);(5,2);(6,2);(7,2);(8,2); (5,1);(6,1);(7,1);(8,1);(5,0);(6,0);(7,0);(8,0); Gain (4,4) (3,5); (3,6);(3,7);(3,8);(2,5);(2,6);(2,7);(2,8); (1,5); (1,6);(1,7);(1,8);(0,5);(0,6);(0,7);(0,8). (-4,-2);(-5,-2);(-6,-2);(-7,-2);(-8,-2); (-4,-1);(-5,-1);(-6,-1);(-7,-1);(-8,-1); (-4,0);(-5,0);(-6,0);(-7,0);(-8,0); (-3,-3) (-2,-4);(-2,-5);(-2,-6);(-2,-7);(-2,-8); (-1,-4);(-1,-5);(-1,-6);(-1,-7);(-1,-8) ;(0,-4);(0,-5);(0,-6);(0,-7);(0,-8). (-5,-3);(-6,-3);(-7,-3);(-8,-3);(-5,-2);(-6,-2);(-7,-2);(-8,-2); Loss (-5,-1);(-6,-1);(-7,-1);(-8,-1);(-5,0);(-6,0);(-7,0);(-8,0); (-4,-4) (-3,-5); (-3,-6);(-3,-7);(-3,-8);(-2,-5);(-2,-6);(-2,-7);(-2,-8); (-1,-5); (-1,-6);(-1,-7);(-1,-8);(0,-5);(0,-6);(0,-7);(0,-8). (-6,-4);(-7,-4);(-8,-4);(-6,-3);(-7,-3);(-8,-3); (-6,-2);(-7,-2);(-8,-2);(-6,-1);(-7,-1);(-8,-1); (-5,-5) (-6,0);(-7,0);(-8,0);(-4,-6);(-4,-7);(-4,-8); (-3,-6);(-3,-7);(-3,-8);(-2,-6);(-2,-7);(-2,-8); (-1,-6);(-1,-7);(-1,-8);(0,-6);(0,-7);(0,-8). Fixed option Gain (4,40%) (-3,30%) Loss (-4,40%) (-5,50%) Probe option (5,30%);(6,30%);(7,30%);(8,30%);(5,20%);(6,20%); (7,20%);(8,20%);(5,10%);(6,10%);(7,10%);(8,10%); (3,50%);(3,60%);(3,70%);(3,80%);(2,50%);(2,60%); (2,70%);(2,80%);(1,50%);(1,60%);(1,70%);(1,80%). (-4,20%);(-5,20%);(-6,20%);(-7,20%);(-8,20%); (-4,10%);(-5,10%);(-6,10%);(-7,10%);(-8,10%); (-2,40%);(-2,50%);(-2,60%);(-2,70%);(-2,80%); (-1,40%);(-1,50%);(-1,60%);(-1,70%);(-1,80%). (-5,30%);(-6,30%);(-7,30%);(-8,30%);(-5,20%);(-6,20%); (-7,20%);(-8,20%);(-5,10%);(-6,10%);(-7,10%);(-8,10%); (-3,50%);(-3,60%);(-3,70%);(-3,80%);(-2,50%);(-2,60%); (-2,70%);(-2,80%);(-1,50%);(-1,60%);(-1,70%);(-1,80%). (-6,40%);(-7,40%);(-8,40%);(-6,30%);(-7,30%);(-8,30%); (-6,20%);(-7,20%);(-8,20%);(-6,10%);(-7,10%);(-8,10%); (-4,60%);(-4,70%);(-4,80%);(-3,60%);(-3,70%);(-3,80%); (-2,60%);(-2,70%);(-2,80%);(-1,60%);(-1,70%);(-1,80%).