GREENWICH, CT—Statistics say that America is more prosperous than ever, but you'd never know it from looking at the horse stables tucked behind the kidney-shaped pool in Fred and Mary Lipton's backyard on Shady Lane.

"We keep meaning to expand them," sighs Mary Lipton, 45, a member of the Greenwich Arts Society and mother of three. "But Freddie's firm has lost several of its corporate clients recently, and we're having a hard enough time making the payments on Crystal Waves [their Bridgehampton home]. When does 'trickle-down economics' trickle down to us?"

The Liptons are at the short end of an alarming trend in America: the ever-widening gap between the rich and super-rich. According to Treasury Department statistics, the wealthiest .01 percent of the American population holds 20 percent of the nation's wealth, or $270 trillion, an amount more than two times the holdings of the next richest .09 percent combined.

The current disparity is an alarming indicator of things to come, according to Martin Hubbell, professor of macroeconomics at Yale University. "A healthy capitalist economy should not concentrate so much of its wealth in the hands of so few," Hubbell said. "I mean, it should concentrate it in the hands of a few, but not so few."

The burgeoning gulf is strikingly apparent on streets like Shady Lane. At its north end, two permanently manned guardhouses mark the entrances to two palatial estates, each more than 5,000 acres, and each just one of many properties owned by its inhabitants.

Yet only a scant two miles away, on Shady Lane's dreaded "South Side," 25-room dwellings like the Liptons' huddle pathetically a few yards from the pavement, the desired effect of their décor often undermined, the nearest neighbor usually less than a furlong away. Unlike the super-rich, with their dozen or so properties across the globe, these owners are but one, two, or at most three catastrophic fires away from utter homelessness.

The close proximity of rich and super-rich is a source of frequent tension, according to Mary Lipton. "There is no doubt in my mind that a lot of [the super-rich] would be very happy to keep us in these slums," she said with a tinge of bitterness in her voice. "Either that, or they just don't want to know about us. It's like, 'Well, as long as I don't have to see them or go into their neighborhood, I can pretend that everything is fine, that everybody has a membership at Pebble Beach and Augusta like me.' It's really palpable. Their maids even act like they're as good as we are."

Indeed, Professor Hubbell detects signs of a budding class-warfare in this year's electoral results. "Ninety-six percent of those with $4 million or more in annual earnings voted for Bob Dole," he observed. "But among those whose income is between $1 and $4 million, the figure plummets to 90 percent. We are dealing with a politics of resentment, and it's going to get ugly."

The owner of one of Shady Lane's two tony northern properties sees no cause for panic in the statistics. "As we say in my industry, a rising tide lifts all ships," said Henry Humphries, a shipping magnate worth an estimated $750 million. "It just takes some time, that's all. Look, I made $45 million last year, and I bought all my executives BMWs. Would I have liked to have bought them Rolls Royces? Of course. But I have to acquire other companies with that money so I can continue to make money so that they can continue to make money. That's what makes the world go around."

But Minnie "Bubbles" DeLaroue, a wealthy widow and Humphries' neighbor across the creek, is quick to acknowledge the problem. The billionairess is founder of Reaching Out, a charity organization dedicated to improving the lives of the less fortunate. "We all need to give back to the rich," said DeLaroue. "My husband believed that what made America truly great was people reaching out to other people, lending them a hand or a houseboat or whatever it takes. In the end, having lots and lots of money isn't nearly as important as just having lots of money."