Royal African Company Share Prices during the South Sea Bubble

Price bubbles provide a unique opportunity to test whether investors act rationally and have sufficient knowledge of the economic environment in which they trade. We focus our attention on the 1720 South Sea bubble episode as experienced by a company not involved in governmental debt financing—the Royal African Company. Following the example of the South Sea Company, the Royal African Company lent its funds to equityholders at a preferential rate. Recognizing this benefit along with the announced dividends explains a large portion of the bubble. Furthermore, the unexplained residual does not behave like an exploding bubble, casting doubt that speculative excess motivated market participants in 1720. Our findings are indeed consistent with investor rationality, and the unexplained residual suggests that we are missing information that was available to the British financial market in 1720.