This dissertation reports a series of studies on social influences in decision making with wide ranging marketing implications in areas such as gamification initiatives, participative pricing mechanisms, and charity fundraising strategies. The body of this work comprises of three indepth, stand-alone studies.

The first study, “Contagion of the Competitive Spirit: The Influence of a Competition on Non-Competitors”, investigates the influence of a competition on noncompetitors who do not participate in it but are aware of it. In a series of experimental studies, the study shows that the mere awareness of a competition can affect a non-competitor’s performance in similar tasks. These experiments provide confirmatory and process evidence for this contagion effect, showing that it is driven by heightened social comparison motivation due to mere awareness of the competition. In addition, the study finds evidence that the reward level for the competitors could moderate the contagion effect on the non-competitors.

The second study, “The Negative Effects of Precommitment on Reciprocal Behaviour: Evidence from a Series of Voluntary Payment Experiments”, examines the effects of precommitment on reciprocal behaviour towards a forthcoming benefit. Through a series of experiments in several countries, the study shows that precommitment often weakens reciprocal behaviour. In two field experiments, a laboratory and an online experiment, the study finds consistent evidence that voluntary payment amounts decrease for individuals who are asked to precommit their payment. The results from a final online trust-game experiment support the posited mental-accounting mechanism for the effect.

The third study, “Hold-Up Induced by Demand for Fairness: Theory and Experimental Evidence”, explores the domain of hold-up and fairness concerns. While recent research suggests that fairness concerns could mitigate hold-up problems, this study proposes a starkly opposite possibility: that fairness concerns can also induce hold-up problems and thus significant inefficiencies. The study reports theoretical analysis and experimental evidence of hold-up in scenarios in which it will not occur if agents are purely self-interested, but could occur if they care about fairness at ex post negotiation.