Using data from the United Nations Comparison Project and the Penn World Table, we find that machinery and equipment investment has a strong association with growth: over 1960–1985 each extra percent of GDP invested in equipment is associated with an increase in GDP growth of one third of a percentage point per year. This is a much stronger association than found between growth and any of the other components of investment. A variety of considerations suggest that this association is causal, that higher equipment investment drives faster growth, and that the social return to equipment investment in well-functioning market economies is on the order of 30 percent per year.

This paper presents evidence on the characteristic speculative dynamics of returns on stocks, bond, foreign exchange, real estate, collectibles, and precious metals. It highlights four stylized facts. First, returns tend to be positively serially correlated at high frequency. Second, they are weakly negatively serially correlated over long horizons. Third, deviations of asset values from proxies for fundamental value have predictive power for returns. Fourth, short term interest rates are negatively correlated with excess returns on other assets. The similarity of the results across markets suggests that they may be due to inherent features of the speculative process.