A lot is written these days about declining birthrates in Western countries and Japan. The most frequent statistic cited is the number of live births per woman in a population: in order for the population to replace itself and remain stable, that number must be about 2.1.
Obviously there are many factors that could complicate the calculation of this “replacement number”. An increase in war and pestilence would tend to raise it, since more births would be necessary in order to make up for an increased death rate. In the opposite direction, improved medical care and decades of peace would tend to reduce the replacement number.
But what governs the increase or decrease in a country’s population in any given year is the number of births compared with the number of deaths.
This morning I stumbled upon a table at Infoplease which shows the birth and death rates per 1,000 population for various countries, most of them European. To determine the rate of increase or decrease, I used the following method to calculate a ratio between the population at the beginning of the year and that at the end:
(Start population of 1,000 + number of births – number of deaths) ÷ 1000, then subtract 1.
A positive ratio indicates that the population is increasing, and a negative one that it is decreasing.
For example, for Australia in 1975 the birth rate was 16.9 per 1,000, and the death rate was 7.9 per 1,000, yielding the following calculations:
1000 + 16.9 — 7.9 = 1009
1009 ÷ 1000 = 1.009
Subtract 1 and you have a ratio of .009, which is the rate of increase.
In contrast, consider Japan in 2007, with 9.2 and 9.4 respectively:
1000 + 9.2 — 9.4 = 999.8
999.8/1000 = .9998
Subtract 1 and you have a ratio of -.0002, which is a slight decrease in population.
Using these methods I built a trend for each country. This is example is for Australia:
The table of ratios for fifteen countries is below (Denmark, Sweden, and other countries of interest were not in the Infoplease table, unfortunately):
– – – – – – – – –
What’s immediately noticeable is how much of an outlier Israel is. It has a substantially higher birth rate than the others, and a remarkably low death rate. The trend of its ratio is moving downward like the other countries, but it is much farther from reaching a stable or declining population than any other nation in the West.
The second graph shows the same group of countries, but without Israel (click the graph at right for a larger version). Removing the latter country allows the other trend lines to spread out, and makes it easier to see them.
There are five countries with a negative ratio, meaning that their population is in decline. Belgium has just reached the zero mark, and will presumably cross the line itself in the next few years. The United States is the only country currently showing an increase in the ratio.
Japan’s ratio has undergone a spectacular drop into the negative over the last three decades.
Several factors can contribute to a higher death rate, such as persistent warfare or civil insurrection, bad medical care, or a large proportion of elderly people in the population. The last condition probably accounts for some of the difference in death rates for Western countries. What else could explain why Australia’s death rate is so much lower than, say, Belgium’s? There is, of course, the possibility that countries with the most thoroughly socialized medical systems have inferior health care, and thus a higher death rate.
An aging population obviously also contributes to a lower birth rate. Add to that condition the disincentives to childbearing so readily provided by the welfare systems of Western countries, particularly in Europe, and one can see why the population in these countries is headed for decline.
I presume these statistics are drawn solely from citizens of the countries involved, leaving out any non-citizen residents. In some countries, such as Britain, citizenship is granted fairly quickly and readily to most immigrants, so that the birth rate must inevitably be skewed by the demographic proclivities of the new citizens.
I suspect that if there were a way to remove non-native citizens and their children and grandchildren from the figures, the trend for most of Europe would look very much like that of Japan, which allows almost no immigration.
The United States is undergoing its own demographic shift with the massive migration of Latin Americans across its southern borders. If the last three decades of this influx were removed, our trend line would not be so healthy, and would probably resemble Western Europe’s.
But all of these conclusions are speculative. I leave you with the raw data, the calculated figures, and the graphs. Make of them what you will.