If one wants to witness first-hand the social and income gaps between the races in contemporary New York City, one should probably visit my local supermarket on the Upper East Side of Manhattan. Situated along the bustling thoroughfare of East 86th Street, the store is a large, sprawling, multi-story affair that rather resembles a warehouse and offers a wide array of staples and delicacies, usually of high quality.

But if you look closer at the people there you will notice something quite striking – virtually all the store employees (cashiers, stock boys, delivery people, meat-cutters, security, etc.) are either black or Hispanic, and nearly all the customers are either white or Asian. Welcome to a 21st century "Tale of Two Cities!"

My neighborhood, the Upper East Side, has a somewhat false reputation in the public mind as a haven of extreme wealth and privilege – a veritable Beverly Hills East. Yes, that impression is largely accurate with respect to the deep-pocketed residents of Fifth, Park and Madison avenues, but in many other parts of this alleged oasis of silver spoons live thousands upon thousands of middle-class people (like me) and even poor folks in various housing projects.

But, I admit, the residents of the Upper East Side remain overwhelmingly white (quite extraordinary in a modern city that is at least 50 percent black and Latino). Thus, the realities that one encounters daily in my supermarket clearly attest to how socially and racially segregated New York is in 2013.

According to Census data for 2010, New York's racial pie chart looks like this: 44.0 percent white; 28.6 percent Hispanic; 25.5 percent black; and 12.7 percent Asian (these numbers exceed 100 percent because Hispanics can be classified as any race). More importantly, more than one-fifth (21.2 percent) of city residents lived below the poverty line as of 2012 – and this segment of the population disproportionately comprise blacks and Hispanics (groups that have suffered huge job losses during the recession). Ominously, poverty is climbing, ensnaring at least 1.7 million people in its grip.

The new mayor of New York City, Bill de Blasio, built his wildly successful populist campaign on trying to closing the widening income gap in the metropolis. David R. Jones, president of the Community Service Society, a research and advocacy group, warned the New York Times last September that the chasm between rich and poor poses a dire threat. “We’re three years into a recovery, and the poverty rate is creeping upward,” he said. “I don’t think this has to mean an all-out call for class warfare, but it’s a serious threat to the viability of the city of New York. This is going to drag us all down.”

The numbers are stark – the city's median household income is at $50,895, which sounds like a good middle-class level, but is actually misleading. The Times noted that the bottom one-fifth of the population has a mean income of only about $9,000, while the highest quintile earned about $223,000. The income gap is particularly large in Manhattan, where the bottom one-fifth has an income of $9,635, versus $389,007 for the top fifth.

By race, median household income data in the city as a whole also tells the same story: The average white household earns almost $60,000 annually, followed by Asians ($52,000), blacks ($40,000), and Hispanics ($36,000).

In addition, let's explore how jobless rates vary by neighborhood: a study by the Fiscal Policy Institute estimated that in the third quarter of 2009, the unemployment rate was only 5.1 percent on the (mostly white) Upper East Side, versus figures of 15.7 percent in the (heavily Hispanic) South and Central Bronx and an astounding 19.2 percent in the (mostly black) East New York neighborhood of Brooklyn. On the whole, the city had a 10.1 jobless rate – but again, that figure fails to reveal the true picture of inequality in the city.

"Wall Street might be recovering, but the recession rages on in New York City's Main Street neighborhoods," said James Parrott, FPI's deputy director and chief economist. "In some cases, great disparities exist within neighborhoods.” Parrott pointed out, for example, that in the neighborhoods of western Brooklyn, which includes such varied areas as Brooklyn Heights, Red Hook and Park Slope, white male unemployment was only 3 percent, while 46 percent of black men in this broad region were jobless.

Overall in the city, for that period, 15.7 percent of blacks were jobless, 11.8 percent of Hispanics, 7.3 percent of "white non-Hispanics," and 6.1 percent of Asians. (I suspect the low Asian unemployment rate reflected the large number of small businesses owned and operated by Koreans, Chinese, Indians and Bangladeshis across the city).

I think all these various segments of New York societies collide daily in my supermarket on 86th Street – but without any apparent rancor or revolutionary fervor (at least for now). I suspect that most of the employees work for minimum wage (or somewhat above) and live far from the Upper East Side, while serving customers who live in the neighborhood and probably earn five, 10, 20, 30, 50 times more than they do.

I have seen (white) customers at this store spend up to $300 or more for their weekly groceries in one shopping trip (on their credit cards, of course) – and it occurred to me that the young black lady ringing up the register wouldn't spend that much on food in a month and likely could not even afford to shop in the very establishment she works in. And this same drama plays out in stores, restaurants and businesses across the city – desperately poor workers just hanging on and customers who are largely indifferent to the plight of others whom they regard as a vast, faceless mass of humanity they do not care about.

I can only hope that these workers at my supermarket are unionized, have adequate health care, enjoy some form of job protection and chances of advancement, and raise their children to have better lives than they did. But I'm also a realist – and I fear that the income gap will never really close, at least not in my lifetime.