John Graunt's Bills of Mortality (1662): Birth of Demography

John Graunt’s Natural and Political Observations Made upon the Bills of Mortality, published in London in 1662, was the first serious attempt to find regular patterns in the births and deaths of a whole population. Graunt, a shopkeeper with no formal scientific training, turned decades of weekly parish returns into tables and estimates. His short book is widely regarded as the beginning of demography, vital statistics and epidemiology.

The Bills of Mortality

London’s parishes had issued occasional returns of deaths since the plague outbreaks of the 16th century, and a continuous series of weekly bills began in 1603. The Company of Parish Clerks collected the figures each week and printed them, so that citizens and the court could watch for signs of plague.

The causes of death were reported by “searchers”, usually elderly women appointed by the parish to view each body. Their judgements were rough: categories included “aged”, “consumption”, “fever”, “griping in the guts” and “teeth”. From 1629 the bills regularly listed causes as well as numbers, and an annual summary appeared each December. Wealthy Londoners mostly glanced at the plague count and ignored the rest.

Graunt and his book

John Graunt (1620–1674) was a haberdasher who rose to hold office in the City and in the trained bands, the local militia. He became curious about what the long series of bills might reveal and gathered as many as he could find, going back to the early 17th century.

His book, which carried a dedication to Sir Robert Moray, then presiding over the newly founded Royal Society, appeared early in 1662. It was well received, and King Charles II personally recommended Graunt for membership of the Royal Society, adding that if they found any more such tradesmen they should admit them too. Graunt was elected a Fellow that year. The book went through five editions, the last in 1676 after his death.

What Graunt found

Graunt’s method was simple but new: he checked the figures for errors, grouped them, compared years and districts, and drew cautious conclusions. His main findings included:

• More boys than girls: about 14 male births for every 13 female, a ratio that stayed steady over many years.
• High child mortality: by his estimate about 36 of every 100 children died before the age of six.
• Growth through migration: burials in London regularly outnumbered christenings, so the city could only grow because people moved in from the countryside.
• Population size: by reasoning from births, families and houses, he estimated London’s population at around 384,000, far below the millions some contemporaries imagined.
• Plague patterns: he showed that major plague years stood out sharply from normal years, and argued that the bills under-counted plague deaths, since deaths attributed to other causes also rose in plague years.

He also noted that some causes, such as suicides, accidents and certain chronic diseases, made up a fairly constant share of deaths each year. That observation, that individual events are unpredictable but totals are regular, became a basic idea of statistics.

The first life table

From his data Graunt built a rough table showing how many of 100 people born would still be alive at each decade of age. By his reckoning only about 40 reached 16, about 16 reached 36, and only around 3 reached 66. The figures depended on guesses, since the bills did not record ages, but the idea of a life table proved powerful.

In 1693 the astronomer Edmond Halley, known for his work on comets, produced a much more accurate table from records of the city of Breslau, which did record ages at death. Life tables of this kind became the basis of life insurance and pension calculations in the 18th century.

Authorship and Graunt’s later life

Graunt’s friend William Petty, a physician and pioneer of “political arithmetic”, edited the fifth edition, and some later writers claimed Petty was the true author. Most modern historians reject that view and credit Graunt, while accepting that the two men shared ideas.

Graunt’s own fortunes declined. He converted to Roman Catholicism, which cost him his public offices at a time of strong anti-Catholic feeling, and his property suffered in the Great Fire of London of 1666. He died in poverty in London in April 1674.

Timeline

• 1603: Continuous weekly Bills of Mortality begin in London.
• 1620, 24 April: John Graunt born in London.
• 1629: Causes of death begin to appear regularly in the bills.
• 1662: Natural and Political Observations published; Graunt elected to the Royal Society.
• 1665: A plague year in London brings renewed interest; a third edition appears.
• 1674, 18 April: Graunt dies in London.
• 1676: Fifth edition published, edited by William Petty.
• 1693: Halley publishes his Breslau life table, building on Graunt’s approach.

Why it matters

Graunt showed that ordinary administrative records could answer big questions about health, population and society. Censuses, public-health surveillance, life insurance and modern epidemiology all rest on the habit of counting and comparing that he introduced in 1662.