"energy used by the economy is a proxy of the amount of real work done in our economy," according to charles a. hall. in the 1980s, hall and others hypothesised, "over time, the dow jones should snake about the real amount of work." twenty years later, a century's market and energy data shows that whenever the dow jones industrial average spikes faster than us energy consumption, it crashes: 1929, 1970s, the dot.com bubble, and now with the mortgage collapse.