The Longevity of Famous People from Hammurabi to Einstein David de la Croix IRES and CORE, Universit´ e catholique de Louvain Omar Licandro IAE-CSIC and Barcelona GSE UCLA, February 24, 2015
Introduction Data Biases Conditional Mean Lifetime Survival Laws Comparisons Interpretations Additional Why should economists bother with longevity ? Adult longevity matters for economic choices and growth Transmission of ideas Lucas (2009): “A productive idea needs to be in use by a living person to be acquired by someone else, so what one person learns is available to others only as long as he remains alive. If lives are too short or too dull, sustained growth at a positive rate is impossible.” Incentive to invest Galor and Weil (1999): “The effect of lower mortality in raising the expected rate of return to human capital investments will nonetheless be present, leading to more schooling and eventually to a higher rate of technological progress. This will in turn raise income and further lower mortality...”. 2 / 53
Introduction Data Biases Conditional Mean Lifetime Survival Laws Comparisons Interpretations Additional Research Question Adult longevity is expected to display no trend in the Malthusian stagnation We know it increased widely from the beginning of the 19th century (Human mortality database) Earlier for English aristocrats (Cummins, 2014) When did it start to increase ? for whom ? where ? why ? Did it lead the increase in income per capita? 3 / 53
Introduction Data Biases Conditional Mean Lifetime Survival Laws Comparisons Interpretations Additional Beliefs at the time of the industrial revolution: For Malthus (1798): “With For Condorcet (1794): “One feels regard to the duration of human that transmissible diseases will life, there does not appear to slowly disappear with the have existed from the earliest progresses of medicine, which ages of the world to the present becomes more effective through moment the smallest permanent the progress of reason and social symptom or indication of order, ... and that a time will increasing prolongation.” come where death will only be the consequence of extraordinary accidents, or of the increasingly slower destruction of vital forces.” 4 / 53
Introduction Data Biases Conditional Mean Lifetime Survival Laws Comparisons Interpretations Additional What we do Build a new dataset of around 300,000 famous people born from the 24th century BCE (Hammurabi) to 1879 CE, Einstein’s birth. Data taken from the Index Bio-bibliographicus Notorum Hominum (IBN), which contains information on vital dates + some individual characteristics. Characteristics are used to control for selection and composition biases. Allows us to go beyond the current state of knowledge and provide a global picture. 5 / 53
Introduction Data Biases Conditional Mean Lifetime Survival Laws Comparisons Interpretations Additional Contribution 1 Adult mean lifetime shows no trend over most of history . It is equal to 59 . 7 ± 0 . 19 years during four millennia. ֒ → confirms the existence of a Malthusian era. 2 Permanent improvements in longevity precede the Industrial Revolution . Steady increase starting with generations born 1640-9, reaching 68 years for Einstein’s cohort. → lends credence to hypothesis that human capital ֒ was important for take-off to modern growth 3 Occurred almost everywhere over Europe , not only in the leading countries, and for all observed (famous) occupations . 4 Reasons to be found in age-dependent shifts in the survival law . → early tendency of the survival law to rectangularize. 6 / 53
Introduction Data Biases Conditional Mean Lifetime Survival Laws Comparisons Interpretations Additional The IBN Index Biobibliographicus Notorum Hominum , aimed to easily access existing biographical sources. Compiled from around 3000 biographical sources (dictionaries and encyclopedias); Europeans are overrepresented. Famous People : ≡ included in a biographical dictionary or encyclopedia. Hammurapi; 1792-1750 (1728-1686) ante chr.; ... ; Babylonischer k¨ onig aus der dynastie der Amorer; Internationale Bibliographie de Zeitschriftenliteratur aus allen Gebieten des Wissens. Einstein, Albert; 1879-1955; Ulm (Germany) - Princeton (N.J.); German physicist, professor and scientific writer, Nobel Prize winner (1921), Swiss and American citizen; Internationale Personal Bibliographie 1800-1943. 7 / 53
Introduction Data Biases Conditional Mean Lifetime Survival Laws Comparisons Interpretations Additional Biographical Sources 80 1 0.9 70 0.8 60 0.7 50 0.6 40 0.5 0.4 30 0.3 20 0.2 10 0.1 0 0 1600 1625 1650 1675 1700 1725 1750 1775 1800 1825 1850 1875 1900 1925 1950 1975 Time Distribution of the 2,781 Biographical Sources. Dashed - frequency (left axis), solid - cumulative (right axis) 8 / 53
Introduction Data Biases Conditional Mean Lifetime Survival Laws Comparisons Interpretations Additional Sources - examples Four haphazard examples of sources written in English language: A Dictionary of Actors and of Other Persons Associated with the Public Representation of Plays in England before 1642. London: Humphrey Milford / Oxford, New Haven, New York, 1929. A Biographical Dictionary of Freethinkers of all Ages and Nations. London: Progressive Publishing Company, 1889. Portraits of Eminent Mathematicians with Brief Biographical Sketches. New York: Scripta-Mathematica, 1936. Who Was Who in America. Historical volume (1607-1896). A complement volume of Who’s Who in American History. Chicago: The A. N. Marquis Company, 1963. 9 / 53
Introduction Data Biases Conditional Mean Lifetime Survival Laws Comparisons Interpretations Additional Number of observations 1000000 100000 100000 10000 10000 1000 1000 100 100 10 10 1 1 -2450 -2150 -1850 -1550 -1250 -950 -650 -350 -50 250 550 850 1150 1450 1750 Number of Observations by Decade, density (dots) and cumulative (solid) 10 / 53
Introduction Data Biases Conditional Mean Lifetime Survival Laws Comparisons Interpretations Additional Our database The digital version of the IBN contains around one million famous people whom last names begin with letters A to L. The retained database includes 297,651 individuals: born before 1880 known years of both birth and death lifespan smaller than 15 or larger than 100 years were excluded, (729 and 872 respectively). 11 / 53
Introduction Data Biases Conditional Mean Lifetime Survival Laws Comparisons Interpretations Additional Control variables From birth and death places: 77 cities with at least 300 observations – as either birth or death place From description: all relevant words with at least 300 observations: 171 occupations, 65 nationalities and 10 religions Source publication date → distance with birth of person Precision dummy, Migration dummy, +8 other characteristics Gender, with the help of a name database Note: took care of translations in 22 languages. 12 / 53
Introduction Data Biases Conditional Mean Lifetime Survival Laws Comparisons Interpretations Additional The universe Upper class – top 10% of society < 1550 1550-1649 1650-1699 1700-1749 1750-1799 1800-1849 1850-1879 Religion 16.7% 22.3% 20.8% 15.6% 9.3% 7.4% 4.9% Army 3.4% 5.3% 7.1% 8.7% 12.1% 7.5% 4.4% Education 18.7% 24.0% 23.0% 22.6% 20.9% 23.4% 26.5% Art 10.9% 11.7% 11.2% 11.5% 10.9% 13.2% 14.5% Law 12.4% 12.8% 12.1% 14.1% 16.6% 14.2% 12.7% Humanities 4.6% 3.6% 3.4% 3.6% 4.0% 6.7% 8.7% Science 4.8% 4.2% 4.7% 6.2% 7.8% 10.2% 12.3% Business 2.8% 3.3% 4.5% 6.0% 7.6% 9.7% 10.0% Nobility 11.0% 4.9% 4.2% 3.2% 2.5% 1.0% 0.4% Unknown 14.7% 8.2% 9.0% 8.6% 8.2% 6.7% 5.7% Women 1.4% 2.2% 2.5% 2.5% 3.3% 3.4% 4.0% 13 / 53
Introduction Data Biases Conditional Mean Lifetime Survival Laws Comparisons Interpretations Additional Unconditional mean lifetime Descriptive statistics: mean lifetime by ten-year cohorts without any control Smoothing: when n t < x λ t = ( n t / x ) l t + (1 − n t / x ) λ t − 1 otherwise, λ t = l t l t and λ t are the actual and smoothed mean lifetimes, n t the actual cohort size, and x is an arbitrary representative size (set to 400) Initial condition: λ −∞ = 60 . 8, from Clark (2007) for hunter-gatherers 14 / 53
Introduction Data Biases Conditional Mean Lifetime Survival Laws Comparisons Interpretations Additional Unconditional mean lifetime 95 85 75 65 55 45 35 25 15 -2460 -2160 -1860 -1560 -1260 -960 -660 -360 -60 240 540 840 1140 1440 1740 Unconditional Mean Lifetime. Note: sample mean for individuals born before 1640 = 60.9. 15 / 53
Introduction Data Biases Conditional Mean Lifetime Survival Laws Comparisons Interpretations Additional The notoriety bias To compute the life expectancy at age a of a population: death rate ���� T d s � E a = ( s − a ) × × S s , a N s � �� � ���� s = a age survival function S s , a is the probability of reaching age s if one has reached age a : � � 1 − d s S s +1 , a = S s , a × N s Problem: N s is the population at risk . That is, the population of people already famous at age s . Unobserved. 16 / 53
Recommend
More recommend
