Maesuring the gap between rich and poor

Income alone doesn't say enough. [Link]

[I]f we compare the incomes of the top and bottom fifths, we see a ratio of 15 to 1. If we turn to consumption, the gap declines to around 4 to 1. A similar narrowing takes place throughout all levels of income distribution. The middle 20 percent of families had incomes more than four times the bottom fifth. Yet their edge in consumption fell to about 2 to 1.

Let’s take the adjustments one step further. Richer households are larger — an average of 3.1 people in the top fifth, compared with 2.5 people in the middle fifth and 1.7 in the bottom fifth. If we look at consumption per person, the difference between the richest and poorest households falls to just 2.1 to 1. The average person in the middle fifth consumes just 29 percent more than someone living in a bottom-fifth household.

To understand why consumption is a better guideline of economic prosperity than income, it helps to consider how our lives have changed. Nearly all American families now have refrigerators, stoves, color TVs, telephones and radios. Air-conditioners, cars, VCRs or DVD players, microwave ovens, washing machines, clothes dryers and cellphones have reached more than 80 percent of households.

As the second chart, on the spread of consumption, shows, this wasn’t always so. The conveniences we take for granted today usually began as niche products only a few wealthy families could afford. In time, ownership spread through the levels of income distribution as rising wages and falling prices made them affordable in the currency that matters most — the amount of time one had to put in at work to gain the necessary purchasing power.

At the average wage, a VCR fell from 365 hours in 1972 to a mere two hours today. A cellphone dropped from 456 hours in 1984 to four hours. A personal computer, jazzed up with thousands of times the computing power of the 1984 I.B.M., declined from 435 hours to 25 hours. Even cars are taking a smaller toll on our bank accounts: in the past decade, the work-time price of a mid-size Ford sedan declined by 6 percent.