We construct a model of a worker's effort choice that includes altruism, warm glow and reciprocity towards employers, as well as the standard cost of effort and monetary incentive motives. We estimate the model using a natural field experiment with temporary workers. We design the experiment so as to structurally estimate the key parameters, using variation in pay schemes and the returns to the employers. Here, we register the analysis plan, including the fully specified structural model.
Update Sep 2018: We add to the registry as an attachment (in the Analysis Plan as well as in the Docs sections) a pre-registration of a follow-up experiment with a new, between-subjects design. This new experiment is entering the field towards the end of September 2018. We anticipate combining both the previously registered and completed experiment as well as the new pre-registered experiment in the same paper.