We test for changes in price behavior in the longest crude oil price series available (1861-2008). We find strong evidence for changes in persistence and in volatility of price across three well defined periods. We argue that historically, the real price of oil has tended to be highly persistent...

We examine the golden age of U.S. innovation by undertaking a major data collection exercise linking historical U.S. patents to state and county-level aggregates and matching inventors to Federal Censuses between 1880 and 1940. We identify a causal relationship between patented inventions and...