Shortly before Canadian soldiers fought a war on the Korean peninsula, the average Korean's "share" of their national economy was worth $770 (all figures adjusted for inflation to 1990 Geary-Khamis dollars). In comparison, Canada's per person economy in 1950 amounted to almost ten times that at $7,437 (again, in 1990 inflation-adjusted dollars). And while Korea's economy was small, other have-not countries in 1950 were similarly tiny. The average per capita share of GDP in the Congo for example, was not much better, at $1,289.

Fast forward to 1998 and South Koreans were prosperous to a degree unimaginable one half-century before. Per capita income grew, in real terms, 17-fold since 1950 to stand at over $13,317 in 1998 - or about two-thirds of the $20,000 per person income in Canada in that year. Alas, during the same 50 years, the Congolese did not see even a doubling in their wealth. Fifty years on, the per-person economy of the Congo was worth just $2,239.

If history can teach us anything, and as the example of South Korea illustrates, it should be that prosperity, better health and longer lives are indeed possible. In his landmark book - literally 2,000 years in the making (!) - economist Angus Maddison looks back over the last two millennia and notes the tremendous explosion of wealth, health, and longevity, especially in recent years. Published by the Organization for Economic Development and Cooperation (OECD), it's a boring title: The World Economy - A Millennial Perspective. But anyone who turns past the first page will discover a treasure trove of nations and peoples that prospered when they paid careful attention to what worked for their more successful neighbours.

But it was not always so. Go back to the year 1000 and the average infant - if it survived - could expect to live only to age 24. Technologically, European ships and navigation were no better in A.D. 1000 than in the Roman Empire.

But, slowly, life began to slowly improve and Madden cites three main reasons; the conquest or settlement of relatively empty areas which had fertile land; international trade and capital movements; and technological and institutional innovation.

Madden's research reveals that while progress did occur between the turn of first millennium and more recent times, life spans, health, and prosperity accelerated more noticeably after 1820, and even more so after 1950. Most encouraging is the recent rise of non-Western countries such as the newly industrialized East Asian "tigers." Their growth rates over four decades means that Hong Kong and Singapore have not only caught up but surpassed their former colonial master, Great Britain, in terms of per capita wealth. Whether the Dutch in 1600 or the Asian tigers in the last 50 years, trade pays tremendous dividends.

As a result, the world is much improved at the beginning of the 21st century; the average life expectancy is 66 years - almost triple what it was in 1000 and almost double what is was in 1820. But, with disparities that range from an African expectancy of 52 years to the long-living Japanese (age 81), Madden's work points the way for the Congo and other have-nots to imitate the now-successful countries. That will include property rights and open trade among other necessary policies.

But trade is a two-way street. And if the still-poor countries of the world are to be the next success story of the modern trading age, the now-richer countries of Europe, North America, and increasingly those in Asia and even Central America, must open up their markets. The history of the last one thousand years - and especially since 1820 and 1950 - shows how critical it is that such trade liberalization occur, especially for the world's poorest.