At the time, Thomas Malthus believed this lack of growth outside Britain was due to the carrying capacity of their local environments.
[1] Great Britain escaped the 'Malthusian trap' because the scientific and technological breakthroughs of the Industrial Revolution dramatically improved living standards, reducing mortality and increasing longevity.
[citation needed] The Victorian era was a time of unprecedented population growth in Britain.
[4] Economist Gary Becker argued that at first, falling fertility is due to urbanisation and lower infant mortality rates, which diminished the benefits and increased the costs of raising children.
(The second demographic transition occurred due to the significant cultural shifts of the 1960s, leading to the decline in the desire for children.
One theory is that greater prosperity allowed people to finance marriage and new households earlier than previously possible.
[9] The evening out of fertility rates at the beginning of the 20th century was mainly the result of a few big changes: availability of forms of birth control, and changes in people's attitude towards sex.