The poorer you are, the more conspicuous is your consumption.  Blacks and Latins are generally poorer than whites.  So:

An African American family with the same income, family size, and other demographics as a white family will spend about 25 percent more of its income on jewelry, cars, personal care, and apparel. For the average black family, making about $40,000 a year, that amounts to $1,900 more a year than for a comparable white family. To make up the difference, African Americans spend much less on education, health care, entertainment, and home furnishings. (The same is true of Latinos.)

Two U. of Chicago economists and another from U. of Pennsylvania researched the matter.  The conspicuous consumption part they got from Thorstein Veblen, who coined the term.  The idea is to prove you’re prosperous, so you can hold your head up in the world.

So preachers of the good life to blacks and Latins might zero in on bling and say forget it, go for the gold of upward mobility through delayed satisfaction. 

But what about that “same income, family size, and other demographics” that seems to make it racial or race-cultural or historically determined race-cultural or something else?  I do not know, but Virginia Postrel takes a crack at it at The Atlantic-dot-com.