Table 4 Sensitivity of the Time Parameter and WTP to the Observed Characteristics
Personal CharacteristicExponentialHyperbolic
ρWTPμWTP
Mean0.195 (0.00)***1,380 (0.00)0.455 (0.06)***2,168 (0.05)b
Reservoir usera0.327 (0.00)***−232 (0.85)0.912 (0.00)*−349 (0.86)
Pivot user0.389 (0.00)***−349 (0.55)1.230 (0.00)*−1,033 (0.32)
Low efficient peer0.085 (0.15)2,611 (0.00)−0.031 (0.89)4,486 (0.03)**
High efficient peer0.163 (0.00)***1,579 (0.00)0.370 (0.12)2,409 (0.05)**
  • Note: p-values for the estimates from the bivariate probit with personal characteristic for fixed time parameter shown in parentheses beside the estimates. We round p-values < 0.001–0.00.

  • a The subgroups (reservoir user, pivot user, low efficient peer, and high efficient peer) come from the four clusters we identify from a kmeans cluster analysis with a Euclidean similarity matrix. We name each cluster by looking at the mean values of the explanatory variables in each cluster and consider how the mean values within the cluster deviate from the mean values for the whole sample.

  • * p < 0.1;

  • ** p < 0.05;

  • *** p < 0.01.