Say researchers are interested in thorough and truthful answers to a questionnaire. How can they incentivize respondents to provide such answers? Simple monetary incentives do not work: paying more for longer answers would incentivize babbling. More generally: in many social or market interactions, requests of economic significance can not be accompanied by common economic incentives.

One approach to such situations is to choose the language of a request strategically. Bruttel et al. (2021) study how adding the phrase “thanks in advance” to a request affects effort in answering a questionnaire. In a simple lab experiment, they ask participants to explain their behavior in a previous task as thoroughly as possible. The treatment difference is whether or not participants additionally see the phrase “thanks in advance.”

Surprisingly, participants exert less effort when seeing the phrase “thanks in advance.” They spend 30 to 50 seconds less on answering the question and tend to write shorter answers. This result shows that even tiny lapses in language can have noticeable consequences on cooperation in such a small-stakes environment, underlining the importance of considering language carefully – in any context.

Why do they react in this way? Possibly, participants could feel that using this phrase is impolite and react reciprocally. However, participants across treatments rate the phrase as very polite and react negatively nevertheless. Alternatively, it might feel like the researchers really do expect them to fulfill the request, leaving them no choice. Then, the participants might react negatively to this reduction of their autonomy.

Lisa Bruttel (University of Potsdam)
Juri Nithammer (University of Potsdam)
Florian Stolley (University of Potsdam)

The paper, titled “’Thanks in Advance’ - the Negative Effect of a Polite Phrase on Compliance with a Request,”can be viewed here and is forthcoming in the German Economic Review.