Friday, August 28, 2009

How To Mislead With Statistics

From treehugger, a Lester Brown article on how to rethink food production for a world of eight billion:
"The shrinking backlog of unused agricultural technology and the associated loss of momentum in raising cropland productivity are found worldwide. Between 1950 and 1990, world grain yield per hectare climbed by 2.1 percent a year, ensuring rapid growth in the world grain harvest. From 1990 to 2008, however, it rose only 1.3 percent annually."
This sounds like disaster in the works. What Mr. Brown doesn't do is compare the rates of increase of population and food production on the same graph. Looking at a table of world population growth, we see that in 1962 and 1963, the rate of population increase was 2.19 percent. But those were the only years in which the rate was over 2.1 percent. So between 1950 and 1990 food production outstripped population. Now since 1990 the rate of population increase has declined steadily, reaching 1.25 in 2000 and 1.11 percent this year. So, once again, the rate of food production is higher than population.

Although this part of the piece is misleading, he has an interesting discussion of various techniques, especially doublecropping, which might be possible. And he doesn't hit the locavore/organic drum at all.

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