Historians and economists point to favorable climate as an advantage enjoyed by Europeans so that these countries developed early, became wealthier, and dominated the globe through innovation, military aggression, and trade. I wondered whether unpleasant climate saps work motivation.
One way of analyzing this question is to look back in time and ask why ordinary people first began to accumulate a level of wealth never before seen. In other words, why did the Industrial Revolution happen?
The Industrial Revolution
Worker productivity, or the value realized by each hour of paid work began rocketing higher in England after about 1870 and never stopped. Productivity increased from $2.55 in 1870 to $27.45 in 1998 (in constant dollars, 1) making Britons more than ten times wealthier in real terms than they were at the beginning of this growth spurt. Similar trends are seen in all developed countries.
With increased worker productivity came higher wages and increased spending that fueled further growth. Yet that phenomenon failed to materialize in some countries around the world. So as far as material prosperity is concerned, these are less well off than the British in 1870 (examples include Burundi, Central African Republic, Liberia, and Democratic Republic of the Congo all having current GDP per person of less than $1,000). Why that is the case is the subject of much head-scratching. One widely floated explanation concerns climate, the notion that in some places it is just too uncomfortable to work hard.
Tropical Climate Versus Tropical Diseases
My own study of 60 countries finds that people are less productive if they happen to live in countries having tropical climates. In other words, they generate less national income per hour of work (including self-employment and employees). Interestingly, people living in countries having temperate climates were not more productive than other countries as one would expect if discomfort from heat and humidity was dragging down work effort elsewhere.
Even if tropical countries are less productive on average, this does not mean that it is the climate that is getting them down. It could be that residents are less productive because they are sicker. Tropical climate exposes people to many nasty parasitic diseases, such as malaria, sleeping sickness, liver flukes, and river blindness. Such illnesses cause fevers, pain, discomfort, insomnia, malaise, and chronic itching. Sufferers are less likely to be productive workers.
Given the prevalence of such illnesses in tropical countries, there is a real increase in the burden of disease and life expectancy declines. The United Nations calculates a measure of the disease burden in a country by calculating the number of healthy life years that are subtracted by a combination of chronic illness and premature death. This is called, disease-adjusted life years, or DALY for short.
I wondered whether the low productivity in tropical countries might be due to the greater burden of disease in those countries. Using regression analysis, I found that once the disease burden is controlled for, tropical countries are not significantly less productive than other countries in the world. This means that residents of tropical countries are less able to work productively because they are sicker.
An optimistic interpretation of this finding is that if tropical diseases can be better controlled many countries will enjoy much faster economic growth. This is one reason that organizations like the Gates Foundation are so keen to wipe out diseases like malaria in Africa and around the world.
So climate need not be a drag on economic growth. Indeed, some of the most productive economies are in places such as Hong Kong and Singapore that have tropical climates. Of course, they also have excellent healthcare systems that minimize the burden of tropical diseases and allow residents to lead lives that are not only long and healthy, but also highly productive.