Managing the Health Impacts of Climate Change through Sector Projects 23 respondents are hypothetical. The use of hypothetical scenarios is in fact the most significant critique made of CVM. CVM is often equated with “willingness-to-pay” studies, which can, at times, give the false impression that using CVM consists of surveys with few questions related to willingness to pay. However, a serious and credible application of CVM is demanding and must follow some specific steps and protocols to produce credible results, as reviewed below. Step 1 Defining the hypothetical situation for consideration by the respondents is the first step. The hypothetical situation must be clearly and precisely defined; together with survey respondents and the suggested change in environmental quality. Step 2 The next step is to determine the type and size of the sample, ensuring that the sample is representative of the entire population and sufficient to yield statistically significant results. Step 3 The third step describes the approach by which the survey will be conducted (e.g., by mail, telephone, or interview). Step 4 The fourth step is the survey design, the most critical part of the process, entailing several sub-steps. It starts with a focus group discussion to test the wording of the survey questions and the overall methodology and approach. The focus group discussion will help developing the questionnaire, which will be pre-tested and then finalized. A key issue in survey design is the elicitation method (i.e., how precisely will the willingness-to-pay question be presented to the respondent?). There are three (3) main elicitation methods: (i) (ii) (iii) Step 5 Open-ended. The respondent is asked to “state” his/her highest willingness to pay (values are not suggested to the respondent). Close-ended. The respondent is presented with a specific value (in local currency) and is asked whether or not (Yes or No) he/she would be willing to pay this amount (this is also referred to as a dichotomous choice). Payment card. The respondent is presented with a sequence of potential payments (in local currency) and is asked to select the highest value that he/she would be willing to pay. The final step is to compile and analyze the results. The data is compiled and analyzed using statistical techniques appropriate to the type of question. CVM (or willingness-to-pay study) is a complicated, lengthy, and demanding methodology. To ensure overall quality, the sample of respondents must be selected correctly and the survey must be properly designed, pre-tested, and implemented. The survey questions must focus on specific changes in environmental goods or services and the changes (against a “no-change scenario”) have to be clearly defined and understood by survey respondents. If respondents do not clearly understand what they are being asked to pay for (hypothetically), then the stated estimates will not be a reliable measure of the true willingness-to-pay. Estimates of the economic costs of climate change on health would generally find their use in the context of a cost–benefit analysis aimed at reducing the impacts of climate change on health. The concept of cost–benefit analysis of adaptation options is described below.