is directed we allowed participants to choose the donation recipient not only among a list of charities
with diverse missions, but also by indicating an alternative charity.9 10 The option of not making
any contribution was also present, in which case the money would remain in the research fund, but
nobody exercised it. Compared to the Baseline, in the two treatments the job is then characterized
by a pro-social dimension, represented by the charitable donation. Notice that in both treatments
it is the student’s choice that determines whether a donation is made at all as well as to which
charitable cause the donation is contributing to.
Comparison of effort obtained across the three treatments allows us to assess the relative
strength of the two alternative sources of pro-social motivation in the workplace. In particular,
comparing the changes in effort we observe in the two sessions between Treatment A and the Base-
line allows us to detect any effort due to action-oriented altruism, while the changes in effort we
observe in the two sessions between Treatment B and Treatment A allows us to detect any effort
due to output-oriented altruism. In the following section we present a simple framework that makes
these predictions regarding workers’ behavior in the three treatments more precise.
To summarize, our experimental design shuts down alternative channels which might cause
workers to act pro-socially in the workplace, such as the expectation of future labor market rewards
(career concerns) or peer pressure. Also, we believe that reciprocity (gift exchange) toward the
employer related to the personal compensation can be ruled out for several reasons. First, on
average these students were making the standard undergraduate RA hourly wage and therefore it
is unlikely that their compensation would be received as very generous. Second, the use of piece rate
compensation means that any additional effort is remunerated and thus reduces the possibility that
workers use effort as a way to reciprocate toward the employer. Finally, as personal compensation
is the same across control and treatment groups what we measure when comparing productivity
across them is effort induced by either type of altruism, over and above effort induced by feelings
of reciprocity toward the employer, if any.
2.3 Conceptual Framework
In this section we present a simple specification of a worker’s utility function and derive optimal
effort in three working environments that correspond to the three treatments that are part of our
design. This framework helps us formulate the main behavioral predictions that we then evaluate
9Four subjects indicated an unlisted charity of choice.
10To ensure the credibility of the donation, subjects were also asked to indicate whether they wanted to receive a
thank you email from the charity. Slightly more than half of the subjects opted to receive a note.