Merchants in the Later Roman Empire is an analysis of the social and economic lives of merchants, traders, and artisans in the 2nd to 4th centuries. It focuses, in particular, on the strategies adopted by merchants participating in small-scale local and regional trade and argues that concerns about social status were the primary determinants of merchant behavior. It expands the traditional application of New Institutional Economics to include informal and social institutions and considers how social norms limited and shaped merchant economic behavior. In doing so, the project moves discussions about the Roman economy away from the effect of the power, and particularly the institutional power, of the state toward a more dynamic model that accounts for the effect of interpersonal relations on the economy. Merchants in the Later Roman Empire argues that the Roman Empire rarely intended to regulate merchant activity in a comprehensive way and was more concerned with maintaining the status quo through its legislation and taxation. It contends that merchants engaged with the state at local levels where personal connections were critical. These ties were structured along similar lines to those between merchants and their peers, competitors, and customers—in short, to the connections they had with individuals throughout their communities. Taking reputation as its focus, this project argues for the institutional power of social norms in merchant social and economic life and analyzes the strategies used by merchants to present and advance themselves. Merchants invested heavily in their reputations and attempted to display their contributions to society, their good characters, and their success in business. These efforts were costly and every form of self-representation relied heavily on the disposition of the audiences to which they were directed. Merchants in the Later Roman Empire considers both the projection and the reception of reputation to conclude that these social norms constrained merchant actions in ways that limited their indiscriminate pursuit of profit but also generated economic opportunities by fostering trust and reducing market volatility.