How does population growth affect the standard of living?

The standard of living increases with the density of the population.

A higher standard of living comes from an efficient division of labor and increased trade. When each member of a society is allowed to do what they can do with the greatest competitive advantage and freely trade the results of their labor and other resources with others who do the same it results in the highest possible standard of living. A larger population provides for a more efficient use of resources, including labor, by increasing the opportunity of trading what one does best for that produced by another.

Examples of high population density with a lower standard of living, when found, can be explained by restrictions placed on the trade or interactions of the people.