Abstract: Understanding the interaction of reciprocal behavior and reputation concerns is important because these two features are prevalent in many economic relationships, like those in the labor market. In particular, we analyze the interaction within the framework of positive and negative reciprocity. There is an agreement in the literature that in one-shot environments, negative reciprocity is stronger than positive reciprocity. Our research question is whether this result still holds when reputation concerns are introduced. We conduct a lab experiment with investment games where we implement both one-shot games (no reputation concerns) and repeated games (reputation concerns). We also manipulate the cost function for punishment and reward: they can be either costless or coslty, where the marginal costs for both punishment and reward are symmetrical.