On Exponential Growth and Half-Lives: A Comment on Bermingham.

A recent paper (hereafter referred to as the "Paper"), Bermingham (2003), presented what appeared to be an analytical review of current situation of declining population growth rates in many parts of the world. The Paper suggested that the increasing growth rates before about 1970 constituted exponential growth, but that the currently declining growth rates were not exponential growth. Hence, the paper asserted that we should not use the terms "exponential growth" and "doubling times" in describing the current situation. Many of the suggestions in the paper are contrary to established mathematics. These suggestions are examined here in some detail. [ABSTRACT FROM AUTHOR]