Aggregate health expenditures as a share of GDP have risen in the United States from about 5 percent in 1960 to nearly 14 percent in recent years. Why? This paper explores a simple explanation based on technological progress. Medical advances allow diseases to be cured today, at a cost, that...

The post-World War I period has seen substantial changes in the world income distribution. As a result, the shape of the distribution has changed from something that looks like a normal distribution in 1960 to a bimodal 'twin peaks' distribution in 1988. Projecting these changes into the future...

Per capita income in the richest countries of the world exceeds that in the poorest countries by more than a factor of 50. What explains these enormous differences? This paper returns to an old idea in development economics and proposes that complementarity and linkages are at the heart of the...

December 15, 1998 -- Version 1.0 <p> The property that ideas are nonrivalrous leads to a tight link between idea-based growth models and increasing returns to scale. In particular, changes in the size of an economy's population generally affect either the long-run growth rate or the long-run level...</p>

What explains the enormous differences in incomes across countries? This paper returns to two old ideas: linkages and complementarity. First, linkages between firms through intermediate goods deliver a multiplier similar to the one associated with capital in a neoclassical growth model. Because...

In 1961, Nicholas Kaldor highlighted six "stylized" facts to summarize the patterns that economists had discovered in national income accounts and to shape the growth models being developed to explain them. Redoing this exercise today shows just how much progress we have made. In contrast to...