Inequality can be measured in a number of different ways, some of which are accurate in today's world however others are more outdated and not very accurate due to the euro centric view of development and inequality. Measuring inequality is not easy, but looking at specific data of country has allowed a measurement to be fairly accurate.
One of the oldest and simplest methods has been to look at a countries GNP, which is the money generate from products and services sold outside the country and also money generated within the country. The GNP is a fairly good measure of inequality, as richer countries tend to have a good health care system, infrastructure and the living conditions tend to be good for a majority of the population. Poorer nations with low GNP a basic or no health care system in place, the infrastructure tends to be undeveloped in many regions and living condition are poor.
There is a strong correlation between GNP and developments stage at which the country is. However looking at GNP exclusively is a simplistic way of comparing and identifying inequality between countries or within them. There are many exceptions to the rule that high GNP equals high development. One example Is Saudi Arabia which is described to be an "oil rich" country and thus has a very high GNP, comparable to that of many MEDC's. However the quality of life for many of the citizens is poor, the wealth is shared between an elite few. Therefore is GNP were use to measure inequality between countries, Saudi Arabia would not register as a country at a fairly low stage of development, in terms of life expectancy and education.
Other measures can be used such as percentage living in urbanised areas or even the number of...