Yves Charbit - Demographic Dynamics and Development

236 226

237 227

238 228

239 229

240 230

241 231

242 232

243 233

244 235

245 236

246 237

247 238

248 239

249 240

250 241

251 243

252 245

253 246

254 247

255 248

256 249

257 250

SCIENCES

Geography and Demography , Field Director – Denise Pumain

Demography , Subject Head – Brigitte Baccaïni

Coordinated by

Yves Charbit

First published 2022 in Great Britain and the United States by ISTE Ltd and John Wiley & Sons, Inc.

Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted under the Copyright, Designs and Patents Act 1988, this publication may only be reproduced, stored or transmitted, in any form or by any means, with the prior permission in writing of the publishers, or in the case of reprographic reproduction in accordance with the terms and licenses issued by the CLA. Enquiries concerning reproduction outside these terms should be sent to the publishers at the undermentioned address:

ISTE Ltd

27-37 St George’s Road

London SW19 4EU

UK

www.iste.co.uk

John Wiley & Sons, Inc.

111 River Street

Hoboken, NJ 07030

USA

www.wiley.com

© ISTE Ltd 2022

The rights of Yves Charbit to be identified as the author of this work have been asserted by him in accordance with the Copyright, Designs and Patents Act 1988.

Library of Congress Control Number: 2021947914

British Library Cataloguing-in-Publication Data

A CIP record for this book is available from the British Library

ISBN 978-1-78945-050-7

ERC code:

LS8 Ecology, Evolution and Environmental Biology

LS8_3 Population biology, population dynamics, population genetics

SH1 Individuals, Markets and Organisations

SH1_3 Development economics, health economics, education economics

SH3 The Social World, Diversity, Population

SH3_8 Population dynamics; households, family and fertility

Yves CHARBIT

CEPED, University of Paris, France

Demographic dynamics come down to a fundamental equation. Every year the growth or decline of a given population (P) is reduced to the interaction of four variables:

(2020 Total population) = (2019 Total population) + (2019 births) –

(2019 deaths) + (2019 immigration) – (2019 emigration)

From this, three simple definitions follow:

– the difference between births and deaths in a year is the natural increase (natural surplus or natural deficit);

– the difference between immigration and emigration is the net migration (which can be either positive or negative). From the point of view of demographic dynamics stricto sensu, international migrations are much less important than births and deaths;

– the total growth rate is the sum of the two indicators (natural increase and net migration), divided by the population of the previous year. It is expressed as a percentage per year.

Before 1750, when mortality and birth rates were balanced, the world population growth rate never exceeded 0.5%. Between 1750 and the 1930s, it did not exceed 1%. It reached a maximum of 2.1% per year, on average, between 1950 and 1970, when mortality in developing countries fell sharply, without a decline in birth rates. Subsequently, more and more developing countries saw their fertility rate decline, as it did in industrialized countries with the end of the baby boom of the 1950s. The combined effect of these two developments led to a steady decline in the world population growth rate: 1.95% in 1970, 1.26% in 2000 and 1.09% in 2020.

Another aspect of demographic dynamics that is directly related to changes in flows must be mentioned. Their very accumulation determines population stocks . Thus, the rural exodus leads to changes in the distribution between urban and rural areas, which is the process of urbanization. As for the evolution of mortality and birth rates, this is translated by the population’s age–sex distribution, conventionally represented by a pyramid. After the Second World War, developing countries experienced a large annual number of births but, due to high mortality, very few people reached adulthood. This was reflected by broad-based pyramids. In these populations, although there certainly were adults, very few were elderly people. With the gradual decline in the fertility of couples, annual birth rates decreased and the proportions of children and adults rebalanced. The population became older and demographers spoke of “aging from the bottom”. In developed countries, on the other hand, where annual birth rates are lower, the age pyramid has more adults. Over the years, these fall into the category of the third age and we speak of “top-down aging”.

These relative proportions of children, adults and the elderly led to several indicators being established, which address the issue of development. It is common to draw a distinction between consumers and producers or, more precisely, to differentiate the inactive from the active. We thus calculate a dependency ratio , where the numerator includes 0–19 year olds (young people) and those aged 60 and above (the elderly), and the denominator is the working population (20–69 year olds). Globally, the dependency ratio – equal to 75 inactive people dependent on 100 working people in 1970 – decreased to 56 in 2000 and to 53 in 2020. Another analysis was recently developed. Due to the decline in fertility, the cohorts now under the age of 15 will be replaced by smaller cohorts. But, above all, they will access the economically active ages and the relationship between consumers and producers – hitherto unfavorable due to spending on health and education weighing on national budgets – will become favorable. So far, we have provided data on world population, but is this concept actually useful?

From a demographic point of view, after the end of the Second World War, the world appeared to be divided into two major groups: developed countries and the so-called “Third World”. The former included North America, Japan, Europe, Australia and New Zealand, whereas the latter included Asia (except Japan), Africa, Latin America and the Caribbean. According to this typology, in 2020, developed countries totalled 1,273 billion inhabitants, i.e. 16.3% of the total world population of 7,794 billion inhabitants 1. But this dichotomy is now outdated, at least in demographic terms, due to the growing disparities between the three continents in which developing countries are located ( Table I.1and Figure I.1).

Table I.1. Population (2020, in millions) and annual growth rate in the major groups (2015–2020 average, in %)

(source: UN DESA 2019)

Annual growth rates reveal that it is necessary not only to contrast the virtual stagnation of developed countries (0.26%) against the demographic dynamism of developing countries (1.26%), but also to differentiate the rapid growth in Africa from the now more moderate growth observed in Asia and Latin America.