Mexican Population Explosion (By Mark Andrew Dwyer)

January 11, 2005: Mexican Population Explosion (By Mark Andrew Dwyer


By Mark Andrew Dwyer – January 11, 2005

While I was researching data for my last week's column “Confusing the Cause With an Effect” about causality relations between the explosive growth of Mexican population, the insolvency of Mexico's economy, and mass outflow of Mexican surplus labor to the U.S. (see [1]), I noticed that some authors have already reached a “consensus” about a permanent decline in Mexico's population growth down to 1% a year.

This, in turn, has made them optimistic about a possibility of bringing the mass and uncontrolled Mexican “migration” to an
end by strengthening the Mexican economy to the point where the Mexicans will not be interested in “migrating” to the U.S. anymore, so that Mexico will not export its population surplus to the U..S. Indeed, as reported by Associated Press (see [2]), Mexico's population grew by “only” 1.1 million in 2004 to reach a total of about 105.9 million, a 1.04% annual increase that is well below that nation's historic growth of slightly above 3% a year.

Unfortunately, these recent figures tell only half of the story, as they don't include the rapid (est. 5% a year or more) growth of the population of Mexican ancestry in the U.S. This fact makes the mentioned above optimistic predictions of purely economic solution of the mass “migration” problem, based on reported slowing down of Mexico's population growth, a futile, if not naive, hope.

Here are the details.

Over the past 70 years, Mexico exhibited remarkably stable population growth,quadrupling its population just in 47 years between 1933 and 1980, which translates on an average 3% a year population growth. Although this growth had its ups (4.6% in 1950 and 7.2% in 1970) and downs (0.4% in 1960), most of the actual annual growth rates (that may be computed using data in [3]) do not deviate much from the average in that period. Only after 1980, these growth rates begun showing a steady decline, staying below 3% a year in early 80- ties, and below 2% in late 80-ties and in the 90-ties, to reach the present 1% in 2004.

A natural question to ask here is what caused such a decline. Obviously, the growing population paired with limited living space and stagnant economy must have negatively affected fertility rates of Mexican women, but it's very unlikely that the overpopulation was the only, or even the main reason of the decline. After all, Mexican two-tier society does not exhibit uniform behavioral patterns in reaction to over-crowdedness, and quite understandably, so.

White elietes, mostly descendants of Spaniards, accustomed to ample living space and comfortable living standards show much less tolerance of the negative effects of the overpopulation than Mestizos, often born and living in poverty and in crowded households, do. As a result, the fertility rates (measured in the average number of children a woman will have in her lifetime) among white women are more likely to decline, as a result of Mexico's rapidly growing population, than the fertility rates of Mestizo women. It seems
natural to assume that these were mostly the declining fertility rates of white Mexican women and not Mestizo women that contributed to the slow down of the Mexico population growth.

On a long run, though, such a selective drop in fertility rates among a segment of population will not persist, as the more fertile women will give birth to more children that are likely to inherit their mothers natural fertility rates and their resistance to overcrowding. If the difference between these two fertility levels is significant enough (as, e.g., between 2.1 and 3.6 that are often quoted as current fertility rates of white and Hispanic women in the U.S.), the segment with lower fertility will show a tendency to decline exponentially to zero, thus making the national fertility converge to the higher of the two and eradicating the temporary decline in the
population growth.

Another, and much more robust, factor is the outflow of excess of Mexican labor to the U.S. As children born to Mexican Mestizo women are less and less likely to find decent living standards and relatively well paying jobs in Mexico, they are more and more likely to seek a living space and employment opportunities in the U.S. In a sense, the U.S. is slowly but steadily becoming an extension motherland, sort of a colony, if you will, for the Mexican nation.

Taking this into account, and the fact that in year 2004 alone est. 4 million Mexicans crossed (illegally) the American-Mexican border in
their search for “better lives”, if one wants to find out to what the actual Mexican population growth is, both the populations of Mexicans in Mexico and in the U.S. must be accounted for.

Below are some statistics; the first column is the year the population was measured or (in the case of Mexicans in the U.S.) estimated; the second column is the population of Mexicans in Mexico (see [3]), the third column is the population of residents of Mexican ancestry (including both Mexican-born and American-born residents, see [4, 5]), the fourth column is the total of the two, and the fifth column is the total's increase, adjusted annually.

Yr. Mexico U.S. Total Avg. growth
per annum

1940 19.8 mln 1.0 mln 20.8 mln –
1950 26.3 mln 1.3 mln 27.6 mln 2.9%
1960 35.0 mln 1.7 mln 36.7 mln 2.9%
1970 50.7 mln 4.5 mln 55.2 mln 4.2%
1980 69.7 mln 8.7 mln 78.4 mln 3.6%
1990 81.2 mln 13.5 mln 94.7 mln 1.9%
2000 100.3 mln 21.6 mln 122.0 mln 2.6%

Fig. 1. Estimated population of residents of Mexican ancestry in Mexico and in
the U.S.

In particular, over the period 1970 – 2000, the total population of residents of Mexican ancestry in Mexico and in the U.S. grew on an average 2.7% per annum, a number that is quite consistent with that nation's historic (1940 -1970) population growth of slightly above 3% a year, minus the effect of fertility drop among white Mexican woman as a result of overpopulation, as well as with estimated 2.7% to 3.4% annual growth rate in major Latino communities in Southern California.

Conclusions and Predictions

Despite the recent drop in population growth in Mexico, the total population of residents of Mexican ancestry in Mexico and the U.S. continues to grow exponentially at a robust rate of 2.5% or more per annum, and there is no good reason to believe that this rate is going to decline substantially anytime soon.

On the contrary, as the percentage of higher fertility Mexican women increases, this growth rate is likely to approach the historic 3% a year. Even if that rate stays at the 2.5% level (rather an optimistic assumption), that will double the current total population of residents of Mexican ancestry in less than 29 years (see NOTE below), that is, to astounding 244 mln by the year 2034. Assuming that the rate of growth of Mexico's population will stay at the current 1% a year level, Mexico's population will reach about 140 mln by the year 2034, with all the excess (the difference between 244 mln and 140 mln), or about 104 mln residents of Mexican ancestry, living in the U.S., thus multiplying their number of 21.6 mln for the year 2000 by a factor of five (5) – quite an explosion by any reasonable standards. (No doubt why they are populating the U.S. – see also [6]).

There is more bad news for us, Americans, in that story. As Mexico's national IQ is about 87 (see [7], table 6.1), and judging from the past experience, we don't even get average intelligent Mexicans with the current wave of mass “migration”, the U.S. national average IQ of about 98 (see [7], table 6.1) will continue to decline because (according to [8], p. 298) IQ is very highly inheritable. This phenomenon is known under the name of dysgenic fertility (see [8], pages 348-357, and [9]) and it takes place when segments of population with below average IQ (e.g., U.S. population of Mexican
ancestry, see [8], pages 341 and 360-361) exhibit above average fertility. As a result, the average productivity will drop, as will average workers' skills.

The high school dropout rate will increase, though, unless academic standards are further watered-down. Health care costs are likely to soar as low IQ has a strong statistical correlation with person's unhealthy lifestyle and a lack of self-care. For instance, prevailing obesity that disproportionately targets residents with below average IQ, will add tens thousands of dollars of a bypass surgery cost to the statistical insured. For similar reasons, crime rates should be expected to grow as criminal activity is strongly correlated
with low IQ (see [8] for more details).

And I haven't even mentioned any of the negative effects of overpopulation under the circumstances of shrinking reserves of natural resources, like land, water, fresh air, and oil, just to name a few.

All the above seem certain like that 2 + 2 = 4. Unless, of course, our Federal government gets serious about enforcing the American border and the immigration laws. But don't expect that to happen any time soon as our corporate elites, out of concern about region's “stability”, corporate profits, and Army recruitment, will vigorously push whoever occupies the White House to not obstruct the free flow of people through our Southern border.


Here is approximate formula, very helpful in evaluating an impact of
population growth:

Years needed to double the population = 72 divided by annual growth rate (in %).

For instance, 72 / 2.5 = 28.8, so it takes about 28.8 years to double the population that grows steadily at a 2.5% annual rate.


[1] Confusing the Cause With an Effect

[2] Population study: Mexico is world's 11th-most populous country, with 105 million people in 2004

[3] Mexico: Historical Demographical Data of the Whole Country

[4] The Mexican-origin Population of the United States in the Twentieth Century (Table 2)

[5] The Hispanic Population in the United States, March 2000 (There are roughly 21.6 million Hispanics of Mexican descent in the United

[6] Why Are Mexicans Populating the U.S.?

[7] R. Lynn and T. Vanhanen, “IQ and the Wealth of Nations”,
Praeger Publishers, 2002

[8] Richard J. Herrnstein and Charles Murray, “The Bell Curve”,
Simon and Shuster, 2nd Edition, 1996

[9] New Evidence of Dysgenic Fertility for Intelligence in the United States