Middle class, hard to define, but includes at least owning a car
The swelling middle class in emerging economies is transforming the economic balance of power across the globe. Measuring it, however, is no easy task. There is no widely accepted definition of what constitutes the middle class, and the most common ways of measuring its growth -- through looking at rises in income -- suffer from a number of flaws.
Next: middle class means cars, meat, toothpaste, cell phones, and air-conditioners.
There's an easier way. In the developing world, buying a car is virtually synonymous with entry into the middle class. In these countries, car ownership separates those with the ability to purchase many other nonessentials from those within the wider population. Car statistics, moreover, are generally reliable and frequently updated, and they include data by automobile type that can be used to further segment the middle class. For this reason, the number of passenger cars in circulation serves as the most reliable gauge we have about the size of a country's middle class.
Applying this measure significantly alters our understanding of the middle class in the developing world. It shows that there are many more affluent people in developing countries than had previously been thought and that about 70 developing countries with a combined population of about 4 billion are near or above the point where car ownership rises very rapidly. This suggests that very large numbers of people will enter the middle class in the coming years, transforming the economies and political systems of the countries they inhabit.