Question

Explain the importance of per-capita measurements when comparing GDP between states or countries

Answer 1

GDP per capita is a measure of the economic performance of a country which accounts for its numbers of citizens. This separates the gross domestic product of the country by the population at large. That makes it a good measure of the standard of living in a country. It tells you how prosperous a country feels for every person there.
When you want to measure GDP per capita between nations, you'll need to use parity of purchasing power. This produces economic balance, or equality, by comparing a basket of identical products. It is a complex calculation that measures the currency of a nation by what it is able to buy in that nation, not just by its value as determined by its exchange rate.

US GDP in 2018 was $20.54 trillion.4 But one reason America's so wealthy is that it has so many people.
After China and India the United States is the third most populous nation. As of 2018, the United States will spread its wealth to 327.2 million people. As a result the United States of America2018 Per capita GDP had been $62,794. Which makes it one of the most stable per individual nations. China has the highest GDP in the world, by some calculations. It generated $25.4 trillion (purchasing power parity factoring) in 2018. Yet its per capita Income was just $18,237, and it has four times as many people as the United States.

The European Union, at $22.4 trillion, is the second-most developed economy in the world. It is an economy made up of 27 different countries. Its per capita GDP was only $43,738 as it has to distribute the wealth among 513.2 million people. India's GDP was $10.5 trillion, but its GDP per capita was $7,763 spread across its 1.35 billion people. Japan's GDP is the fifth-largest in the world, $5.4 trillion. Its per capita GDP was $42,798 as it has a population of 126.5 million.