There are differing levels of economic development between countries. Wealthier countries with high standards of living are called more economically developed countries, while poorer countries with low standards are called less economically developed countries. Countries can be compared using gross national product per capita in US dollars, but this only provides an average and may not accurately capture living conditions. To better understand relative wealth, additional statistics on population, social factors like healthcare and education, and economic data should be considered. The wealth gap exists because less developed countries often have low industrialization, rely on agriculture and mining, cannot afford imports, lack infrastructure and power, face political instability or natural disasters, and have less education.