A striking characteristic of high-tech products is the rapid decrease of their quality-adjusted prices. Empirical studies show that the rate of decrease of QAPs is typically not constant over time; QAPs decrease rapidly at early stages of the product and then the rate of decrease tapers off....

Machines are more expensive in poor countries, and the relation is pronounced. It is hard for a Solow (1956) type of model to explain the relation between machine prices and GDP given that in most countries equipment investment is under 10% of GDP. A stronger relation emerges in a Solow (1959)...