Major tensions in the welfare debate concern how to handle situations in which we are unable to distinguish between those who are deserving and those who are undeserving. We report from the first economic experiment designed to study how people make trade-offs between giving money to some who are undeserving, false positives, and not giving money to some who are deserving, false negatives. We study the behavior of a representative sample of 2000 participants from the US and Norway, who were asked to distribute a sum of money between two groups of workers. In the first group all workers had done an assignment, but in the second group a number of the workers had falsely reported to have done the assignment. We find that the willingness to equalize income betweenthe two groups is decreasing in the number such cheaters in the second group. A large majority of the participants in both countries is, however, more concerned with avoiding false negatives than with avoiding false positives. We also find that the aversion to false negatives is related to political preferences, with right-wing voters being more concerned with false negatives than left-wing voters. Our results suggest that political disagreements is not only about what should be viewed as deserving, but also about how to handle situations in which we cannot distinguish between those who are deserving and those who are undeserving.