2014 年 12 巻 2 号 p. 105-111
People may refuse trade-offs between some things that they value and other things. However, the possibility that some values are protected against being trade-offs with other values can make an appropriate judgment regarding public works impossible. The purpose of this study was to examine the effect of providing opportunities for reflection regarding protected values (PVs) on the changes of the PVs. For this purpose, we conducted an experiment targeting university students (n = 98), where subjects were asked to think of counterexamples in which protected values (PVs) around public works (dam construction project) conflict with other values. We investigated the effect of such an experimental manipulation upon respondents' expression of PVs. The results showed that reflective thinking on PVs can lead people to make a trade-off with other values and then PVs can be changed. Especially it was found that those who could reflect over other values than PVs through the experimental manipulation tend to change their expression of the PVs. Finally, implications of the present results for consensus building around public works were discussed.