Per capita
Definition
The term per capita is used to refer to the total quantity divided by the population size. More specifically, the term per capita is (total amount of across the population) divided by (size of population).
Note that:
- In some cases, it does not make sense to measure that quantity for individual people. For instance, a country can have a total foreign aid spent in a year by the government, and we can divide by the country's population to obtain a foreign aid spent by the government per capita in that year. It does not, however, make sense to ask how much each individual in the country has spent on foreign aid.
- In other cases, it makes sense to measure the quantity for individual people, and the total for the population is the sum of the quantities for each individual. In this case, the per capita value represents the arithmetic mean across the population. Due to variation within the population, people could have higher or lower quantities than the per capita value, and we can talk of the distribution of the quantity across the population. Note that in this situation, the per capita value is an arithmetic mean and not a median. If the distribution is not symmetric but is skewed to one side, the arithmetic mean and media could differ considerably.