Do biodiversity conservation videos cause pro-environmental spillover effects?

We examine whether audio-visual media interventions that aim to increase donations towards biodiversity conservation cause pro-environmental spillovers on two subsequent behavioural intentions: The Willingness to Pay (WTP) a green fee and Willingness to Donate (WTD) time to an environmental campaign. In a controlled lab experiment, we exogenously vary the media exposure to brief biodiversity conservation videos and media content on the anthropogenic cause of biodiversity endangerment. We find media exposure has a positive spillover effect on the likelihood of stating a positive WTP, but not on WTD. Media content on the anthropogenic cause of biodiversity endangerment has both a direct causal impact on the amount donated, and an indirect positive effect on the time volunteered, especially for pro-social subjects who have donated to charities outside the lab. These results highlight that media content (on the anthropogenic cause) can cause positive short-run pro-environmental behaviours when there is behavioural similarity (i.e., voluntary contributions of money and time) for subjects who hold a stronger pro-social identity (past donors).