Table S2.

Study 2 endowment effect regression results

Variables	ΔEndowment effect
Δ Insula activation			3.262 (1.518)*
Item set order	0.566 (0.194)*	0.569 (0.194)*	0.478 (0.190)*
Age		−0.001 (0.019)	−0.014 (0.024)
Σ Insula activation			−0.833 (1.006)
Constant	−0.513 (0.137)**	−0.514 (0.143)**	−0.396 (0.151)*
R2	0.37	0.37	0.53
N	15	15	15

Robust SEs (clustered by subject) are in parentheses. The constant reflects the endowment effect decrease from session 1 to session 2, controlling for other regressors in the model. Because the set of items differed between session 1 and session 2, we calculate change scores by taking the average of the four observations at session 1 subtracted from those at session 2. Age was centered at the median because of skewness. Sum of insula activation was mean centered. *P < 0.05; **P < 0.01 (two-tailed).