This time is different: An example of a giant, wildly speculative, and successful investment mania

The literature on manias and bubbles is dominated by spectacular collapses and the question of whether they could have been foreseen. What is not widely known, though, is that there was at least one giant and wildly speculative investment episode that was successful in that it produced above-market profits for original investors. The British railway mania of the 1830s involved real capital investment comparable, as a fraction of GDP, to about 2 trillion for the U.S. today. It faced withering skepticism and criticism, much of it very reasonable, as its supposedly rosy prospects were based on extrapolation from the brief experience of just a couple of successful early railways. Yet by the mid-1840s, it was seen as a success. The example of the railway mania of the 1830s serves as a useful antidote to claims that bubbles are easy to detect or that all large and quick jumps in asset valuations are irrational. This episode also suggests the need to reexamine much of the work on business cycles and the diffusion of technologies. The standard literature in this area, starting from Juglar and continuing through Schumpeter to more recent authors, almost uniformly ignores large investment mania, whose nature does not fit the stereotypical pattern.