AbstractThis study investigates the effects of ‘time to think’ and ‘ballot box’ on willingness-to-pay, while providing the first empirical evidence on assessing the benefits of an air quality improvement program in urban Africa. Our hypothetical referendum scenario proposes to reduce the air pollution related morbidity rate in Douala, Cameroon by 25 per cent in exchange for a one-time surcharge on the electricity bill of each respondent. We find that on average WTP decreases by nearly one-fourth when allocating respondents time to think but markedly increases when we use a ‘ballot box’ approach allowing respondents to state their willingness privately. Our results suggest that on average households are willing to pay US$0.42 per month (0.2 per cent of household annual income). We conclude that total citywide benefits are unlikely to exceed the costs of implementing such a program at this point, although this situation may change quickly with increasing economic growth.