This Slate column observes that U.S. businesses that cater to the mass affluent are reporting disappointing financial results. It sets out to explain why, and part of the answer is that "yuppie inflation" is rising faster than core inflation.

It opened by saying Starbucks said the reason it's earnings were down was because customers were ordering more frappucinos. They were doing so because of the heat.

Because frappucinos take longer to prepare, that slowed things down and cut into revenues.

Uh huh.

An excerpt:

For years, betting on the ability and willingness of high-end consumers to spend was a winning formula for both retailers and investors. The ranks of the mass affluent were growing, their wallets filled thanks to tax cuts and rising home values. And thanks to the phenomenon of trading up, plenty of people on the lower rungs of the income ladder were splurging on things they were passionate about: golf clubs or shoes, for example. Now the powerful trend seems to be going in the opposite direction. Well-off consumers are reining in spending, and there is likely to be a growing phenomenon of consumers trading in steaks at Morton's for Whoppers at Burger King. As the Wall Street Journal reported, "Burger King Chief Executive John Chidsey told investors during a conference call that the Miami-based chain is benefiting from a slowdown in spending at sit-down restaurants that is prompting some consumers to trade down to fast-food chains." Investors are clearly worried that America is going downscale. Here's a three-month chart of Starbucks, Williams-Sonoma, P.F. Chang's, and Whole Foods against the S&P 500.

Clearly, the bite of inflation, rising interest rates, slow wage growth, low savings, and higher prices is starting to work its way up the income ladder. After all, people with higher incomes pretty much spend everything they make, too. In fact, there's a degree to which upper-crust consumers could be feeling the pinch disproportionately. Depending on where they live, how they work, and what they spend, consumers experience inflation differently. Someone who takes a subway to work won't feel the pain of rising gas prices, while someone who drives a pickup 70 miles to work each day certainly will. A person who takes a loan to buy a gas-guzzling power boat will find that the cost of buying and operating the boat has gone up dramatically; someone who buys a kayak made in China will find that the price of boating is falling.

Merrill Lynch economist David Rosenberg has examined the spending and consuming habits of his colleagues and clients on Wall Street and has created his own "Wall Street core inflation index," which tracks the rise in prices of the necessities of yuppie life: "jewelry, spas, lawn care, health care, sporting goods, housekeeping services, tuition, airlines, hotels, salons, legal/financial services, and dry cleaning." His conclusion: The price of spoiling yourself rotten is rising rapidly. "The Wall Street core CPI is running at 4%, nearly double what it is for Main Street," he wrote in a report on July 28.

In other words, forget about the heat and the Frappuccinos. Sales at Starbucks and its sister high-end retailers may be faltering because the cost of living well is rising more rapidly than the overall cost of living.

As a personal note, while I can't generalize this to all Starbucks, the employees at the local one seem much more focused on yakking with each other than serving customers.

"Starbucks employees like coming to work," one of them told me. "They like their co-workers."

All good. But perhaps they should also develop a passion for serving customers quickly to complement the one they have for emotionally bonding with their co-workers.

This spring, Second Cup suddenly delared its regular size of coffee was now a medium -- and it cost $1.85, not $1.60. That's a jump of more than 15 per cent.

At some point, it becomes an avoidable luxury.