Framing a decision situation differently has affected behavior substantially in previous studies. This paper tests a framing effect in a field experiment at the University of Zurich. Each semester, every student has to decide whether to contribute to two social funds. Students were randomly informed that a high percentage of the student population contributed (or, equivalently, that a low percentage did not contribute), while others received the information that a relatively low percentage contributed (or a high percentage did not contribute). The results show the influence of framing effects is limited. People behave in a conditional cooperative way if informed either about the number of contributors or about the equivalent number of non-contributors. The positive correlation between group behavior and individual behavior is, however, weaker when the focus is on the defectors. The field experiment also shows gender differences in social comparison.