¥ Contingent valuation is enormously flexible  in that it can be used to estimate the economic value of virtually anything.   However, it is best able to estimate values for goods and services that  are easily identified and understood by users and that are consumed in  discrete units (e.g., user days of recreation), even if there is no observable  behavior available to deduce values through other means. 
¥ CV is the most widely accepted method for  estimating total economic value, including  all types of non-use, or Òpassive useÓ values.  CV can estimate use values, as well as  existence values, option  values, and bequest values.
¥ Though the technique requires competent survey  analysts to achieve defensible estimates, the nature of CV studies and  the results of CV studies are not difficult to analyze and describe. Dollar  values can be presented in terms of a mean or median value per capita or  per household, or as an aggregate value for the affected population. 
¥ CV has been widely used, and a great deal  of research is being conducted to improve the methodology, make results  more valid and reliable, and better understand its strengths and limitations. 
                Issues and Limitations of the Contingent Valuation Method:
¥ Although the contingent valuation method has  been widely used for the past two decades, there is considerable controversy  over whether it adequately measures people's willingness to pay for environmental  quality. 
¥ People have practice making choices with market  goods, so their purchasing decisions in markets are likely to reflect their  true willingness to pay. CV assumes that people understand the good in  question and will reveal their preferences in the contingent market just  as they would in a real market.  However, most people are unfamiliar  with placing dollar values on environmental goods and services.  Therefore, they may not have an adequate basis for stating their true value. 
¥ The expressed answers to a willingness to  pay question in a contingent valuation format may be biased because the  respondent is actually answering a different question than the surveyor  had intended.  Rather than expressing value for the good, the respondent  might actually be expressing their feelings about the scenario or the valuation  exercise itself.  For example, respondents may express a positive willingness to pay because they feel good about the act of giving for a  social good (referred to as the Òwarm glowÓ effect), although they believe  that the good itself is unimportant.  Respondents may state a positive  willingness to pay in order to signal that they place importance on improved  environmental quality in general.  Alternatively, some respondents  may value the good, but state that they are not willing to pay for it,  because they are protesting some aspect of the scenario, such as increased  taxes or the means of providing the good.
Advantages of the Contingent Valuation  Method: