gdpI was reading about GDP per capita in the world. http://en.wikipedia.org/wiki/File:GDP_PPP_Per_Capita_IMF_2008.svg
According to this, China has relatively low GDP per capita whereas USA has a lot more. Europe varies.
Do these statistics make sense? It could be that the Eastern region of China, i.e the coastline where about 300 million people live has the same GDP per capita as Western countries, while Western China, has a lot lower GDP per capita, i.e. similar to Afghanistan. By that measure, the Eastern region of China should be regarded as a developed country, not a developing country.
If it doesn’t make sense, why do we still measure most statistics by country?
I think the important question is: What do you want to know?
GDP per capita for a whole country is a useful statistic for getting an overview or looking at the impact of various national policies, or looking at whether there is overall growth or not.
If you on the other hand want to sell Rolls Royce cars in China, it is not that interesting to know what the GDP per capita is. It does not really get more useful if you get the GDP per capita for a specific region or even city. What you want to know is the number of individuals who can afford to buy such a car.
I believe GDP per capita for a whole country is one of the most important measures for the customers of the national offices of statistics, namingly the national government. When that is said, I personally, would like to see reporting of GDP per capita on city-level.
Taken separately, a few of the city-provinces (e.g. Tianjin and Beijing) would be classified as high-income by the World Bank’s scheme, the rest of China would be in the upper-middle income group. You raise a valid point about spatial aggregation, and we all sometimes forget exactly what averages mean (or mean averages), especially when we undertake regression analyses.
But, the problem isn’t entirely ignored–we often are at least as concerned with measures of dispersion as with measures of central tendency. For example, economists put a good bit of focus on the distribution of income. In development economics, we very often consider that income varies across not only over space, but also by gender, landholder status, race and so on. We not only break income down by sub-national boundaries, but we also estimate median household income separately for female-headed households vs male-headed households (and broken down by a variety of other factors). But all that wouldn’t fit on the back page of The Economist, and would require quite a bit of local knowledge to interpret.
This is a sub-case of what’s known in geography as the modifiable areal unit problem. The ways we aggregate spatial data matter, and we can re-aggregate spatial data in different ways to get almost any result we desire. For many purposes, country boundaries are at least as good as any other boundaries since country boundaries usually delineate an area with a common language, history, currency and political regime, thus implicitly controlling for many factors. That is, country boundaries are not nearly as arbitrary as are most sub-national geopolitical boundaries. Thus, countries remain the basic unit of analysis for many analyses. Trade flows are measured at the country level (for good reasons), and monetary (and other) policy is often determined at the country level (also for good reasons).
Perhaps you are objecting to summary statistics in general? Your argument could be carried forward until we require a table of the income of each person on earth. Consider that there are large income differences even in eastern Chinese provinces–maybe we’d do better to just compare Guangdong with the rest of the world since Jiangxi is bringing down the eastern average. For the same reasons, we should knock Mississippi out of the U.S. statistics and Wales out of the UK stats. We’d eventually find that Washington, DC is the most developed region on earth. But the NW part of the city is very different from the SE part. We could go on to require postal code and finally household data. I suppose we could then say that my medical doctor neighbor is more developed than I am. (Admittedly a bit of a straw man argument.)
Keep in mind that classifying countries as developed or developing based only on GDP is a bad idea. To get a better picture you have to look at other indicators: life expectancy, infant mortality rate, etc.
All content is licensed under CC BY-SA 3.0.