In most, if not quite all, parts of the world, the size, shape and longevity of the human body have changed more substantially, and much more rapidly, during the past three centuries than over many previous millennia.

The president has very little effect on the economy. If you want to put blame or credit, the main person who influences the business cycle is the head of the Federal Reserve Bank.

The rate of technological and human physiological change in the 20th century has been remarkable. Beyond that, a synergy between the improved technology and physiology is more than the simple addition of the two.

One of the most startling events in my life was when my older son was about 16, and he blamed me for all the troubles of the world. So I, I felt like telling him, Oh no, I was just like you when I was your age; I wanted to change the world, too.

Centuries ago it may have been difficult for pregnant women and their children to get proper nourishment, probably leading to smaller - and therefore shorter-lived - adults.

Among the current discussions, the impact of new and sophisticated methods in the study of the past occupies an important place. The new 'scientific' or 'cliometric' history-born of the marriage contracted between historical problems and advanced statistical analysis, with economic theory as bridesmaid and the computer as best man-has made tremendous advances in the last generation.

The Quest for Prosperity is an important book. Written with verve and clarity, it reflects a deep understanding of global economic issues, and proposes practical solutions that anyone concerned with the plight of the world's poor would be wise to read.