Hello, I have been teaching a part of a lecture on "Valuation Methods of Natural Resources" where I covered contingent valuation method. Students collected data using a double-bounded contingent valuation method questioning technique and we analysed them with a very simple logLikelihood estimation of a probit function. For the convenience of others who want to do something similar I uploaded the code, data and questionnaire to http://homepage.boku.ac.at/umorawet/Rcode/cvm/ This year I will teach this class again and wanted to know if someone has a more sophisticated function for CVM than I provide on the above linke (and would be willing to share with me and my students), maybe with bootstrapping for the standard errors or inclusion of explaining variables? Maybe it is even possible with one of the packages on discrete choice methods available on CRAN and give me a hint which one to use (though I did an extensive search on this issue)? Thank you, Uli -- Ulrich Morawetz Universit?t f?r Bodenkultur Wien Department f?r Wirtschafts- und Sozialwissenschaften www.boku.ac.at