Now, how about the present situation in the US? Are we, like many European nations, at ZPG ?
No. The mid-2013 rate of natural increase for the US population (r as a percentage) was 0.5%. That is, r = 0.005.
How does r for the US compare to r in other highly industrialized nations? We often hear that we are growing slowly; is this true?
In fact, r for the US is higher than in most industrialized nations (refer to your population fact sheet to check this out, or see the section on ZPG nations). (Exceptions include Australia, New Zealand, Ireland, Iceland, Norway, and France, which have rates as high or higher than we do in the US.)
It is the opinion of the Sierra Club, incidentally, that the US is the most overpopulated nation on Earth. This claim is based on a comparison of consumption patterns worldwide, the assumption being that consumption is proportional to per capita environmental impact. Their comparison suggests that the average US family has the equivalent of 40 children, because per capita consumption rates here are so high. (You should not accept this claim as quantitatively precise; the concept is robust, but the number is soft. Estimates for the ratio of per capita consumption by US citizens to that of citizens of lesser developed nations range from 10:1 to 30:1 or even higher. It depends on which nations are being used in the comparison, and what data are used for estimating per capita consumption.)
We often hear that the US population would be stabilized if it weren't for immigration . While the section below explores the effect of immigration on US population growth in more detail, for now it is sufficient to say that this isn't the case. "r" is calculated based only on births and deaths (b-d). It includes immigration only to the extent that it counts births to and deaths of immigrants.
Immigration is significant in terms of our absolute change in numbers year to year though, as described in the next section of these notes.
(To move to the next section in these notes (on the influence of immigration on US population growth), click the box at the bottom of the page labeled ">>." To return to the previous section, click the box labeled "<<" and to return to the master directory for the BI301 web site, click the box labeled "CONTENTS.")
Page maintained by Patricia Muir at Oregon State University. Last updated Nov. 14, 2013.