Similar results have been obtained in other applications of the quantity design. In an early study using this design, Kahneman and Knetsch (see Kahneman, 1986) found that Toronto residents were willing to pay only a little more to clean up all the polluted lakes in Ontario than to clean up polluted lakes in a particular region of Ontario. McFadden and Leonard (1993) reported that residents in four western states were willing to pay only 28% more to protect all 57 wilderness areas in those states than to protect a single area. Jones-Lee et al. (1995) found that the SWTP of UK respondents for a program to reduce the risk of non-fatal road injuries increased by only 29% when the number of prevented injuries was increased by a factor of three. Laboratory studies show similar insensitivity to the quantity of the good. Baron and Greene (1996, experiment 8) , for instance, found no effect on SWTP of varying the number of lives saved by a factor of 10.