List of countries by GDP (PPP) in the nineteenth century

These are lists of countries in the nineteenth century by their estimated real gross domestic product (GDP) in terms of purchasing power parity (PPP), the value of all final goods and services produced within a country/region in a given year. GDP dollar (international dollar) estimates here are derived from PPP estimates.

Due to the absence of sufficient data for nearly all economies until the 20th century, earlier GDP is only roughly estimated. In a first step, economic historians try to reconstruct the GDP per capita of a given political or geographical entity from the meagre evidence. This value is then multiplied by the estimated population size, another determinant for which as a rule only little ancient data is available.

A key notion in the whole process is that of subsistence, the income level which is necessary for sustaining one's life. Since pre-modern societies, by modern standards, were characterized by a very low degree of urbanization and a large majority of people working in the agricultural sector, economic historians prefer to express income in cereal units. To achieve comparability over space and time, these numbers are then converted into monetary units such as International Dollars, a third step which leaves a relatively wide margin of interpretation.

The formula is: GDP (PPP) = GDP per capita (PPP) x population size

It should be stressed that, historically speaking, population size is a far more important multiplier in the equation. This is because, in contrast to industrial economies, the average income ceiling of premodern agrarian societies was quite low everywhere, possibly not higher than twice the subsistence level. Therefore, the total GDP as given below primarily reflects the respective historical population size, and is much less indicative of contemporary living standards than, for example, estimations of past GDP per capita.

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