The explosion of research on regional economic institutions (REI) over the last two decades has led to a richer understanding of why they emerge, what form they take, and what effects they have. This chapter argues that research on REI is not a monopoly of any particular theoretical, methodological, or epistemological approach. Ongoing work leans not merely on standard political science and economics but on sociology, psychology, and critical theory. Yet, REI studies cluster in silos more often than barns, although this chapter highlights some research programs with potential for fostering barns. Exclusive attention to power, economic efficiency, transaction costs, and transnational normative diffusion—the common analytical currency in standard accounts of REI—may conceal deeper domestic drivers underlying REI dynamics.