The following thesis presents the results and analysis of three distinct experiments. The first features an experimental auction market designed to resemble eBay and other such peer-to-peer markets, including the presence of a reputation mechanism. The results presented suggest that the presence of a reputation mechanism will improve consumer welfare. Further, having a greater number of possible feedback ratings available leads to even further improvements in consumer welfare. The second features a repeated auction that also involves Bayesian uncertainty, about the 'type' of the seller. In addition, we present the predictions of a theoretical model that extends the existing sequential equilibrium literature into multi-player, market-based games. We find that reputational concerns remain an important consideration in such settings. The final experiment examines the role of within group heterogeneity (in the endowment and marginal return) in public goods games. The novel experimental designed allows for a full schema of relationships between the endowment and marginal return. The results presented suggest that there are significant behavioural differences depending on the relationship between the endowment and marginal return. When they are inverse, subject’s absolute contributions are not different. When the two are proportionally related, relative contributions are not different.