Crude Birth Rate (cont.)
The Crude Birth Rate is a useful measure to approximate numbers of births when you have limited information available. If you know that a population is 20 million people and that the CBR is currently 13 per thousand then you can estimate that births in the next year will be about 260,000. For these simple calculations the CBR is fine. It is also an important measure because of its place in the balancing equation.
Disadvantages: A CBR considers the total population in the denominator and treats all ages equally. This is a weakness because the driver of the production of births is the sub-group of women aged 15-49 years and the proportional size of this group can vary considerably between populations. We say that the CBR “is confounded by age structure”. Because of this the CBR is not used as an accurate measure of fertility by demographers. Although it is true that trends in the CBR will be similar to trends in the Total Fertility Rate for any one country, the TFR is standardised for population structure and therefore is a more precise measure of fertility.
Values of the CBR mostly range between 50 per thousand and 10 per thousand. Some levels and trends are shown in Figure 1.
Figure 1: Levels and Trends of Crude Birth Rate
Source: United Nations Population Division