• India’s population growth rate is highly overestimated by existing models, say scientists who suggest that accounting for the diversity and differences in the levels of education among people can help arrive at more accurate projections.
• Accurate population projections could help India and its workforce catch up with more developed Asian countries with higher GDP per capita, researchers suggest.
• India is an extremely heterogeneous sub-continent, the study suggested.
• Simply because it is one nation, unlike composite Europe, it should not be treated as a uniform entity, said Wolfgang Lutz, the World Population programme director at International Institute for Applied Systems Analysis in Austria.
• The forecasts for India over the coming decades strongly depend on which sources of heterogeneity are explicitly included in the model.
Five-dimensional model
• By 2025, India is expected to surpass China as the world’s most populous country due to higher fertility rates and a younger population.
• To account for the diversity between different areas of India, researchers designed a study that pioneered a five-dimensional model of India’s population differences that include rural or urban place of residence, State, age, sex, and level of education.
• The model was then used to show the population projection changes within scenarios that combine different levels of these factors.
• For example, a much higher population projection results from a model that combines data from individual States as compared to the overall national projection, since States with higher fertility rates eventually add up to a higher national population projection.
Age, sex, education
• If the projection is carried out while only explicitly accounting for age and sex, influential factors like higher education, associated with decreased fertility, are left out.
• Thus, a projection based on today’s much higher fertility rate of uneducated and rural women predicts a drastically larger population in the future.
• Depending on the dimensions considered, when fertility, mortality, education and migration rates are frozen at the 2011 levels, stratification by education, States, or residence can result in population projections that span a huge range from 1.6 to 3.1 billion.
• Where these rates change according to plausible model predictions, the population peaks at between 1.65 and around 1.8 billion.
• The difference between projections shows the importance of deciding which demographical measures to include in a projection model, researchers said.
Source
The Hindu 02.08.2018