1018 Journal of Economic Literature,Vol.XLII (December 2004 of experimental methods,but rather in the bject was asked whether he or she terms of t the relevance of convenience sam would be willing to pay $X towards a public ples for the contingent valuation method good,where $X was randomly selected to However,it is easy to see that their methods be $10,$30,$60,or $120.A subject would apply much more generally. respond to this question with a "yes,"a The HL approach may be explained in “no,”ora"not sure.”A simple statistical terms of their attempt to mimic the results model is developed to explain behavior as a of a large-scale national survey conducted for the Exxon Valdez oil-spill litigation.A hanerc observable socioeconomic major national survey was undertaken in this case by Richard Car on et al.(1992)for the oped.HL the ceeded to the eral of the state of Alaska Thi ed ther stat -of-th e sta mor y for preve on this is the HL asked apply to t can obtain is simply mai the sam resu ts us then the statistical mode may be ience sample of stud used to predict the behavior of the target of South Carolina.Using students as a con population if one can obtain information venience sample is largely a matter about the socioeconomic characteristics of methodological bravado.One could readily the target population. obtain convenience samples in other ways The essential idea of the hl method is but using students provides a tough test of hTipnoe oroceeded by developing a sim sentative in the sense of allowing the survey instrument than the one used in the rcher to develon a d"statistical of this is pu model of the behavi or under the of the a not essential to the method.Th at se pi available of the survey wa to a relative the beha of student with stude ta tha rvey th a nts"is the to contro t attributes,is the col variability in their socio-demographic char lection of a range of tandard socioeconom acteristics,not necessarily the unrepresen- ic characteristics of the individual (e.g.,sex tativeness of their behavioral responses age,income,parental income,household conditional on their socio-demographic size,and marital status).Once these data characteristics. are collated,a statistical model is developed To the extent that student samples exhibit in order to explain the key responses in the limited variability in some key characteris- survey.In this case the key re nonse is a tics.such as age.then one might be wary of the veracity of the maintained assumption ce valuation question. In other words volved here.Howey r the sample do e to look like the order for the statistical n odel to be an adequate e one 4 Th xact form of that statistical odel is not impe (9)for et for of this method