A country's standard of living generally depends on the size of its national income. Standards of living are measured by such things as the number of cars, televisions, telephones, computers, washing machines, and so on, for every one thousand people. There is, however, no standard international index, which is why national income figures are used as a substitute. But the use of these figures to compare the standard of living between countries needs to be done carefully, because they are, at best, only a rough guide which can be misleading. The main problem here is that it is necessary to have a common unit of measurement if any sort of comparison is to be made at all. It has become the custom to use the dollar, and each country's currency is converted at its official exchange rate into a national income figure in dollars. Now, since the exchange rate is often set at an artificial level in relation to dollars, you are likely to end up with a figure that is useless for your purposes.

Due to the absence of the standard international index, national income figures are generally applied to measure and compare standards of living with dollars being the common unit, which may lead to the fact that the figures converted can be misleading and useless as the exchange rate of each country is artificially regulated.