In a developing country such as India the contingent valuation method (CVM) cannot always provide a correct valuation of recreational use benefits of an environmental resource given the huge size of the parallel economy involving different categories of middle to upper income group families which have the capacity to move as tourists. The ‘participant observation method’ and ‘unstructured interview schedule’ are necessary tools to be used in such cases, in addition to a ‘structured interview schedule’ which is used for primary data collection in the travel cost method (TCM) and the CVM under normal circumstances. A general model depicting the relation of the ratio of consumer surplus estimated in TCM and CVM with ‘corruption perception index’ has been developed in the case of tourists from various countries with different world rankings in so far as their parallel economy and level of corruption are concerned.