Many economists rely on GDP (Gross Domestic Products) to analyze and compare economies. However, there are several limitations of GDP as all macroeconomic statistics do.
One of the limitations is that ‘nominal’ GDPs do not take into account that there are inflations and deflations. So let’s say that there was 10% inflation and the GDP increased 10%. Some could say that GDP has increased by 10% and that is economic growth. However, it these people didn’t take into account that in fact inflation has caused this increase in GDP. So this is one of the limitation of ‘nominal’ GDP. There is another GDP called ‘real’ GDP that takes inflation/deflation out of the GDP and tries to measure the ‘true’ GDP of an economy.
The second limitation is that GDP does not measure negative externalities. For example, the CO2 emission produced by economic activity would not be considered in measuring GDP. Also, depletion of some resources are not considered either. So, this limitation is greatly criticized by ecological economists.
Another limitation is that GDP’s could change due to change in exchange rate to US dollar. Notice how GDP is calculated in USD. So GDPs of foreign countries would change due to their change in currency value. For example, Japan’s recent GDP would rose due to their strong yen. So, change in currency values could change the GDP. However, this is not the problem of United States because the country uses USD.
There is one last limitation to GDP. It is that GDP’s do not measure black markets and illegal economic transactions. For example, if some drug dealer sells $1 million dollar of drugs to some country this will not be counted in the GDP. Some people will say that these kind of economic activities would comprise only a meager proportion of GDP, however, United States, for example, has 10~20% of illegal black markets to its GDP.
In sum, these were the limitations of GDP. Despite these limitations, GDP is considered to be one of the best methods of measuring/comparing economies.