This paper uses a citizen-candidate model to analyse how the characteristics of the political office drive the valence of the political candidates. We set up a model with a political job composed of several tasks, with random outcomes. Voters observe the quality of the different tasks but not the politician’s valence. The complexity of the political office, measured by the number
of tasks to be undertaken, each task’s difficulty, and their variability, change the valence signal conveyed by the politician’s performance in office. This has an impact on reelection probabilities which change the relative attractiveness of the political job for high and low-valence individuals politicians. We show that the quality of the polity depends on the interaction between self-selection into politics and the screening mechanism of reelections. We then introduce incumbency advantage, and show that the screening effect becomes less powerful. This leads to a lower quality of the polity. We characterise the possibly multiple equilibria of the model with incumbency advantage and show that the only stable equilibrium is the one with highest valence.