Authors: Haojie Chen, Matthew R. Sloggy, Robert Costanza, Ida Kubiszewski, Tong Zhang, Luhua Wu
Deliberation – the process of group discussion and consideration – has been increasingly integrated to valuation of ecosystem services. In an online stated preference survey on the Fanjing Mountain National Nature Reserve in the Southwestern China, we assessed participants' willingness to pay (WTP) for cultural services (non-material benefits gained through interacting with nature, including its ecological and geological elements and characteristics) before and after deliberation. However, among the initial participants, only a subset completed deliberation and the full survey. This dropout of participants may occur in any deliberation-based valuation survey, introducing sample selection bias for estimating the impacts of deliberation. To control sample selection bias, we applied the Heckman correction approach which uses the probability of a given observation being included in the sample based on its other observed characteristics. Overall, deliberation led to a more concentrated distribution of WTP and reduced the effects of sociodemographic drivers of WTP. Deliberation also had varied impacts on different participants' WTP, including increases, decreases, and no change. The median WTP remained unchanged, although the mean WTP became significantly lower after deliberation (even when controlling for sample selection bias that significantly influenced the effects of deliberation). The use value of the Reserve's cultural services for visitors was estimated at approximately 520 million CNY per year based on the pre-deliberation mean WTP, and 314 million CNY based on the post-deliberation mean WTP. This value reflects the Reserve's natural, cultural, and economic significance and the need for continued support for both nature conservation and sustainable tourism management.