An Eye-Opening Measure: The Vital Index

by Carl Haub, senior demographer, PRB

The vital index, the annual number of births per 100 deaths, is a simple measure but can often be eye-opening. Only a few countries publish the index on a regular basis. While that may not sound exciting at first, the measure can teach us a lot about population dynamics. Recently, the index did receive some national news: when the number of deaths of non-Hispanic whites in the United States exceeded births, for the first time in history.

In the table, we can see that the current level of the total fertility rate (TFR), or the average number of children per woman,  does not necessarily show where a country stands with regard to births and deaths. The present vital index is a result of a number of factors: how recently the TFR declined to a low level; the proportion of the population in the older ages; the number of young people who have moved into childbearing ages; and the effect of immigration, which normally consists of workers and their families who are themselves in the childbearing ages. All of these factors play into the vital indices in the table in different ways.

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A Tale of Four Pyramids

by Carl Haub, senior demographer, PRB

There has been quite a bit made in the media and in blogs about low birth rates in industrialized countries. Quite correctly, many people (and countries!) are concerned that unprecedented aging and a dearth of younger people are leading to serious pressure on national budgets from a rising burden of support for the elderly because of  a declining group of tax-paying workers. But the situation is far from equal everywhere, and less is written about that.

The contrast between the age structures of the two country pairs below is striking, to say the least. All four countries have rather stable birth rates. If they stay that way, the demographic future of all four seems quite clear but in very different ways. These differences have profound implications for the future. Sharp shifts to an aging population will result in growing budgetary constraints, less ability to provide aid, and limited foreign policy options.

Populations of France and Germany, by Age and Sex

France and Germany

Source: for France: Institut national d'études démographfiques; and for Germany: United Nations Demographic Yearbook 2011.

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How to Write About the Birth Rate

by Carl Haub, senior demographer, Population Reference Bureau

No demographic subject captures writers’ imaginations like a country’s birth rate, be it baby “booms” or “busts,” or record highs or lows. But what measure should you use when you’re writing about the birth rate? Yes, there’s more than one—there are three: the crude birth rate, the general fertility rate, and the total fertility rate. In this blog post, I want to clear up the confusion.

First, we’ll take the crude birth rate (CBR), which is simply the number of births in a year per 1,000 population. Rates have a numerator (in this case, births) and a denominator (the country’s total population). The fact that the denominator is the total population of all ages is the reason why the CBR is labeled “crude.” In 2011, the CBR in the United States was 12.7 births per 1,000 population. But the CBR can be significantly affected by age structure, so that a population with a high proportion of elderly will tend to have a lower rate than one with a younger population. Why bother to report it? Because the CBR is one of three essential parts of the national population growth rate, since populations grow or decline based on the number of births, deaths, and net immigration—the balance of people moving in and out.

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Writing About Population Projections: Beware

by Carl Haub, senior demographer, Population Reference Bureau

It’s quite common to see reports such as “The United Nations projects that world population will be 9.3 billion in 2050,” a perfectly true statement. Many readers will most likely take that at face value and move on. But they should be asking questions! There are over 200 countries in the world with birth rates from 1.1 children per woman (in Taiwan) to 7.6 (in Niger). In most of those countries, it is the future course of the birth rate that will largely determine population size. The projection of 9.3 billion is just the sum of all the country-level population projections. What should those readers ask? For starters: What does the United Nations assume will happen to all those birth rates over the next few decades?

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