Overconfidence: Does it Increase with Time in Office?

A healthy sense of confidence seems to be fundamental for the exercise of political office, self-assured personalities are regarded to be more competent decision-makers and a high degree of self-confidence appears to be a decisive factor of success in politics. However, an excess of self-assurance – so called overconfidence – can have a negative impact on leadership skills and even lead to severe errors in decision-making. Overconfidence, which describes the positive discrepancy between the subjective expectation about the outcome of a decision and the actual observable quality of a decision and its outcome, does not present a new phenomenon. In fact, psychologists and financial economists have analyzed this behavioral bias for decades. Within the political science research, however, only a few studies explore the effects of this phenomenon. Especially the connection between overconfidence as a personality trait and the individual leadership style has only been examined sporadically. Therefore, this research aims at further exploring the overconfidence phenomenon within the political sphere, particularly in regard to political leadership. In contrast to the belief that with increasing experience one can more realistically assess one’s own and others capabilities as well as other external factors and therefore make more accurate forecasts, this research takes a different approach. The proposed hypothesis is that political decision-makers tend to become more overconfident throughout their time in office instead of better calibrated with increasing experience. To test this hypothesis empirically, US senators who have served six or more terms will be examined regarding their overconfidence-levels over the course of their incumbency. Overconfidence will be measured for each term served by comparing the senators’ confidence with their actual performance in each term. The confidence will be measured by using the assessment-at-a-distance technique developed by Margret Herman for the Leadership Trait Analysis (LTA). Senators’ performances will be assessed by the use of the Legislative Effectiveness Scores (LES) by Craig Volden and Alan Wiseman. In a following step, the two scored will be compared for every term of each senator in order to identify, weather the senators have been overly confident about their performances and how their accuracy changed over time.