Geography Reference
In-Depth Information
Rates of natural increase and their associated “doubling times” (see the “On the double!” side-
bar) have incredible implications for economic development and social well-being. A 2.5 per-
cent rate of natural increase means there will be about twice as many mouths to feed in 28
years; twice as many people in the schools; twice as many people seeking health care, energy,
employment, and transportation. Now, it would be one thing if this pertained to affluent coun-
tries that could adequately meet the needs of their citizens. But what about a poor country?
And indeed, that's the rub. Generally, countries that exhibit the highest rates of natural increase are
relatively poor. Stated differently, the highest rates of population growth are generally taking place in
countries with the least amount of financial resources to address the needs of their growing popula-
tion.
Slow growth, affluent country (with some notable exceptions)
Figure 11-4 includes a “low” category for which the rate of natural increase is under 1.0 percent. That
corresponds to a population “doubling time” of 70 years, so every country in this category takes at
least that long to double its present citizenry (migration not considered). Often, low rates of natur-
al increase coincide with relatively affluent countries. A principal reason is that the economies and
livelihoods of well-to-do countries do not require large amounts of manual labor, so families have
comparatively few children, and that depresses the rate of natural increase. (Additional reasons are
discussed in the next section.)
On the double!
How long does it take a country to double its population given a particular rate of natural
increase? The following table provides some answers. To take two examples, if a country
has a 1.5 percent rate of natural increase, then it will take 48 years to double its popula-
tion, assuming the rate of natural increase does not change in the interim. In contrast, a
3.0 percent rate of natural increase is sufficient to double the population in only 23 years.
Remember that natural increase equals birth rate minus death rate. It does not take into
account either in-migration or out-migration, both of which could be key factors in a coun-
try's population change.
