Hi, Essentially there are market use values, non market use values and non market non use values. These three categories are quite different. Market use value relates to the value of a good or service provided by nature that can be directly termed into monetary terms, such as commercial and recreational fishing; revenues generated by fishermens provide a good incite for that, for recreational fishing, the expenses generated by the consumers. non market use values can be termed as the consumer surplus, or in simpler terms, its the difference between what the consumer is paying the service (even if its 0$) and what he would be willing to pay; often here the willingness to pay (WTP) is used as a benchmark. Non market non use values can be divided into two sections, the option value (that is the value of knowing that I can go and enjoy the service or good) and the existence value (the value attributed to knowing that the good or service - e.g. tropical forest- is still intact. To mesure these values there are basically two major categories, the Revealed preferences (how consumers and producers have interacted in the past) and stated prefences, which are collected using surveys. Examples of revealed preferences are property value, travel cost models (expenditures engaged to provide a specific activity) Examples of the stated preferences are: *Contingent valuation, in which the researcher directly asks the consumer through a survey (e.g. willingness to pay). *Stated choice, different than the contingent valuation (CV) because the interviewee must choose between a range of tradeoff, in contrast to CV which asks what are your preferences, mindless of the costs. I hope this answers, in part the question,