The Demographic Transition Flashcards
Ashraf and Galor 2011
The Malthusian Trap
Paper provides evidence establishing Malthusian dynamics up until 1500 (at least):
- Improvements to technology have a permanent effect on population density, but not income pc (goes up then down)
- This is due to the fixed factor of land, meaning marginal income pc is negative in the population (and decreasing marginal productivity).
- Shocks and technology increase productivity or income pc, leading to greater fertility and child survival, until the bigger population is constrained again by land productivity.
- Implies relatively consistent standards of living across societies, with population density varying with technology and land productivity.
Statistics:
- +1% in years since the Neolithic Revolution (instrumented for by biogeography, to avoid population density being endogenous) occurred there is associated with +0.8% population density, and no variation in income. Explains 40% of variation.
- Variation in land productivity explains 60% of population density variation
- +1% in productivity in 1500 associated with +0.6% population density
Galor and Weil 1999
Unified Growth Theory
Theorises that the escape from the Malthusian trap was driven by the sustained technology growth of the IR. This enabled a growing population to overcome the constraint of land, as marginal productivity was not decreasing. Fertility peaked in early 1870s (Germany, UK), then declined as income pc grew.
The development of technology in the IR increased the returns to child quality and education (returns to human capital), encouraging parents to have fewer and invest more in their education. This then enables more technological advancements (educated population). Rising incomes became allocated to child quality, not quantity (better investment), and at this point the trap was escaped. IR also improved womens’ outside options.
Mortality shocks can create escapes. Positive shocks lead to faster population growth, technology growth, and quality-quantity trade-off. Complementary to or at odds with the Black Death? Implies that escape and transition can occur endogenously, from sustained innovation (rather than focusing on shocks like BD).
Chaney and Hornbeck 2016
Morisco expulsion as a population shock, and how different institutions create different results. Correlates to the Black Death in Europe; in WE it resulted in more freedoms, release from serfdom, and improved conditions, in EE it led to more coercion.
Moriscos made up ~1/2 of Valencia’s population, and were suddenly expelled in 1609. In all regions, income pc rose and populations fell. In less-affected areas (minority Morisco), incomes and pc output converged quickly, but remained differentially higher (and population lower - half life 21 years) in more affected ones.
Explanation: stricter, more taxing institutions persisted in majority M areas, meaning the income effect was not transmitted, and populations failed to rise (fertility did not rise). Explains slowness. Furthermore, these policies discouraged in-migration. Evidence: higher taxes on those regions, more direct control by nobility over time (2x as likely 150y later).
Cultural - stereotypes - M had lower subsistence needs and bigger families (earlier marriage), and hence greater steady state.
Technological - M areas output varied far more with rainfall than C. If C migrants/majorities were able to use C technologically to limit negative variation and maintain high positive variation, explains greater output. Also, regions adapted to scarcer labour by using labour saving technology (bigger farms), with more output pc.
Voigtlander and Voth 2013
“Invention” of fertility restrictions
The Black Death triggered an escape from the M trap, by restricting fertility, by improving women’s outside options. Divergence occurred in 14C, with (W) Europe avoiding ~1/3 of possible births. Suggests this was the cause of the later transition (over late 19C).
Black Death increases land abundance, favouring land-intensive industry (husbandry requires 20% fewer hands per acre). Higher incomes pc also favour luxury goods. Women have comparative advantage in husbandry (luxury), and so have labour opportunities (cheaper). Evidenced in society, with female workers being contractually obligated to avoid pregnancy.
Evidence: proportion of unmarried women (1380) correlates with share of pastoral land in 1290 (indicating suitability to pastoral farming). Grain production (acreage) fell, and livestock rearing rose 90% after BD. Age of marriage correlates positively with level of pastoral farming (instrumented for deserted villages, which created land abundancy). Estimate average increase of 4 years.
Explains: why the European Marriage Pattern was weaker in S Europe - the climate was not suited to husbandry (land abundance had less effect, since grain had greater productivity here than in W Europe), and husbandry was nomadic and less suited to women at the time - and the population recovered faster from BD. Also explains why China did not escape, as they did not switch from grain to pasture; WE reached a new steady state of more income and lower fertility; grain production was 4x as efficient in China, less wage premium for women in husbandry.
Weil and Wilde 2009
Is Malthus relevant today?
Claim - in the absence of a technological change or expansion of a fixed resource, population will be stable. In the absence of a change to the production function (ie innovation), such changes will generate population growth but not living standards.
Poorer countries today exhibit these conditions due to high population growth, resource dependency, and less ability to overcome these constraints through trade.
The Malthusian channel by which population growth lowers income pc (decreasing marginal productivity) is still relevant to poor states (rural, agricultural populations, or reliant on exports of a fixed resource). Implies for a state with 30% income from resources, halving the population would boost income pc by 26%. But this doesn’t explain the 20x income differences between rich and poor nations.
Becker et al 2010
Evidences the importance of education and the quality-quantity tradeoff in the fertility transition (Galor and Weil 1999).
Model: IR technology requires education, leading to more education and the Q-Q tradeoff (as well as meaning parents value education). Triggers the fertility transition. Focus on latter half of the IR, as this is when returns to HC grew. Shock increases value and creates a cultural shift.
Evidence: significance of the Q-Q tradeoff found before the transition (ie, that it occured). In Prussia, education correlates causally with fertility (and vice versa). Education proxied for by inequality (landlords don’t like it) and distance from Wittenberg (Protestantism). Robust to controls (eg wealth levels). So this relationship existed.
In Prussia, a county with more investment in education in 1849 experienced a steeper fertility decline later on. 10% higher in 1849 leads to a decline of 1.3% in 1890. Explains up to 60% of variation in fertility variation.
Education as a major predictor of fertility transition strength, implying human capital had a major role.
