This objective of this paper is to improve the understanding of the increased non-response to transport surveys. We have developed a theoretical model based on the travel demand function and the willingness-to-pay when there is a change in travel price. We consider the non-response as a decision to not reveal preferences. Following Deaton and Irish (1984) and Carlevaro, et al. (2009), we analyzed multiple causes of non-response through a censored model, called the m-hurdle. We tested and estimated the model on the non-responses given to an income question on a survey about pricing change in Lyon (N = 1,500). We showed that non-response can be explained by both—an economic cause linked to the respondent’s lack of resources and a non-economic cause resulting from a rejection of the pricing solution. To decrease the level of non-response, we propose that attention should be paid to the respondents’ contexts, particularly for those with low incomes.