Final answer:
The GDP per capita is the best economic statistic for comparing the standards of living between two countries, as it normalizes GDP by population size.
Step-by-step explanation:
To compare the standards of living in two countries, the most appropriate economic statistic to use is GDP per capita. This measure takes the gross domestic product (GDP) of a country and divides it by its population size, enabling a comparison of economic welfare or standard of living on a per person basis. It addresses two critical issues when comparing across nations: the need to convert GDP into a common currency and the need to account for differences in population sizes. GDP per capita helps to compare countries with varying population sizes, providing a clearer picture of individual prosperity.