Abstract:The current work focuses on non-price policies to achieve residential water conservation, specifically on water conservation campaigns. The authors report the results of a large-scale longitudinal field experiment encouraging residential water conservation among 1500 households. The effectiveness of two commonly-used message phrasings is compared: an assertive and a suggestive message. Assertive messages employ a commanding tone, such as "You must conserve water", whereas suggestive messages employ a more gentle approach, as in "Please consider conserving water". Despite the ubiquitous use of assertive phrasing in pro-social messages, and previous research that suggests that, in some cases, assertive language can increase message compliance, the authors show here that the suggestive, gentler, message language can make a more accentuated change in residential water conservation behavior. This may stem from the status of water as a basic needs resource, which may reduce the appropriateness of freedom restricting language, such as an assertive tone.