The article introduces a new model called economic harmony for understanding decision-making in games. This model suggests that people's satisfaction with outcomes depends on how close they are to their desired outcomes. When players in a game reach a state of harmony, their satisfaction levels are equal. The model was used to predict decisions in different ultimatum games and a common pool resource game, showing good agreement with experimental data. In the standard ultimatum game, the model predicts that the allocator should transfer a portion of the total sum equal to 1 minus the Golden Ratio.