CH 5: Measures, Theories, and Trends of Birth & Fertility

1.) Population Change:

2.) Cohort Measures:

Phenomena's of Population Change: birth, reproduction, fertility & natality

Based on the interaction of 4 vital events: birth, death, in-migration & out-migration

These kind of measures also account for the fertility of martial cohorts

Marital-status-specific rates may be used to determine the effects of customs and traditions in societies that tend to restrict premarital childbirth


Cohort measures are great for long-term analysis

4.) World Fertility Levels & Trends:

The continent of Asia, specifically China & India, have experienced a decline in fertility and the TFR, which went from 3.7 to 2.2

Africa has dealt with a continuous birth explosion since the late 1990's, with an exception to the largely Muslim countries north of the Sahara.

By the early 1960s, a decline in fertility levels began that continues to the present, contributing to todays fertility level, which is at its lowest levels in history.

1.) Measuring Fertility:

Sources of fertility analysis data: vital statistics, censuses & sample surveys

Two ways to measure birth & fertility:

Fertility and fecundity are not the same thing.

  1. Period Measures- synchronous models, measuring # of births happening in the same year/time
  1. Cohort Measures- diachronic models, measuring the fertility performance happening over long lengths of time

2.) Common Period Measures:

  1. Crude Birth Rate (CBR)
  1. Total Fertility Rate (TFR)
  1. Age-Specific Fertility Rates (ASFR)
  1. General Fertility Rate (GFR)
  1. Gross Reproduction Rate (GRR)
  1. Net Reproduction Rate (NRR)
  1. Child-Woman Ratio (CWR)
  1. Zero Population Growth (ZPG)

3.) Theories of Fertility & Important Contributors:

1. Theory of Multiphasic Demographic Response - developed by Kingsley Davis and suggests that declining mortality rates and access to resources has lead to high fertility rates. Attributes the fear of relative deprivation as a reason for families limiting their size.

2. Theory of Intermediate Variables - developed by Kingsley Davis and Judith Blake and argued that an increase in a woman’s birth parity is a result of intercourse, conception & gestation.

4. Diffusion Theories - this theory suggest that the pace of diffusion depends upon the costs and benefits of new fertility control behaviors as well as the spread of new ideas and behaviors associated with family planning
.

3. Economic, Structural & Cultural Theories -

Quality of Children - developed by family-studies specialist, G.S. Becker

Theory of Relative Income - developed by Richard Easterlin

Role of Values and Custom - spearheaded by Ansley Coale

Social Structural Theories

Wealth Flow Theory - developed by John Caldwell

Latin America & the Caribbean region has few very high-fertility populations but has a great amount of TFR variations between the different regions.

4.) Fertility Trends in the U.S:

Pre-Revolutionary War TFR = 8.0 children per married woman; Early 20th Century TFR = below 4.0

U.S. birth rates dropped to their lowest levels in the Depression years of the 1930s

Postwar U.S. fertility levels was dominated by the Baby Boom & by 1947, the TFR rose back to 3.27

The US has one of the highest TFR levels among all of the developed countries but it is still below replacement rate