John Graunt
Early Life
John Graunt was born in London on April 24, 1620, to Henry and Mary Graunt. His father was a draper, and Graunt followed in his footsteps, becoming a successful haberdasher and draper himself. He was the eldest of seven or possibly eight children, though not all survived to adulthood. Graunt's early education is not well-documented, but it is known that he was not university-educated, making his later accomplishments all the more remarkable.
Career
In the 1650s, Graunt took an interest in the bills of mortality, weekly summaries of the causes of death in London. These bills had been produced for several decades, but Graunt was the first to analyze them systematically. He used the bills to estimate the population of London, a feat never before attempted. His methods were rudimentary by modern standards, but they laid the groundwork for the science of demography.
Graunt's work on the bills of mortality culminated in the publication of Natural and Political Observations Made upon the Bills of Mortality in 1662. This book, often simply referred to as Observations, was groundbreaking. It was the first quantitative analysis of mortality data, and it introduced many concepts that are still fundamental to demography and statistics today.
Contributions to Statistics
Graunt is often credited as the founder of statistics. His Observations was the first book to present mortality data in a statistical format, and it introduced many concepts that are still used in statistics today. For example, Graunt was the first to use the concept of a life table, a table showing how mortality rates vary with age. He also introduced the idea of statistical regularity, the notion that large groups of data will exhibit predictable patterns.
Later Life and Death
In his later years, Graunt faced significant financial difficulties. His business failed, and he was forced to sell his membership in the Royal Society. He died on April 18, 1674, just shy of his 54th birthday. Despite his financial struggles, Graunt's contributions to demography and statistics have ensured his place in history.
Legacy
Graunt's work has had a lasting impact on the field of statistics. His Observations laid the groundwork for the science of demography, and his methods are still used in population studies today. He is often referred to as the father of statistics, a testament to his significant contributions to the field.