The greatest threat to democracy in the United States is the growing inequality of wealth. (The causes of that inequality, including the unchecked power of multinational mega-corporations, are important, too.) Thomas Jefferson recognized massively disproportionate distribution of wealth as a possibility. It is now reality.

The situation has gotten serious over the past fifty years, as Robert Lieberman points out in the current issue of Foreign Affairs:

The wealthiest Americans, among them presumably the very titans of global finance whose misadventures brought about the financial meltdown, got richer. And not just a little bit richer; a lot richer. In 2009, the average income of the top five percent of earners went up, while on average everyone else’s income went down. This was not an anomaly but rather a continuation of a 40-year trend of ballooning incomes at the very top and stagnant incomes in the middle and at the bottom. The share of total income going to the top one percent has increased from roughly eight percent in the 1960s to more than 20 percent today.

When we talk about the income of the top one percent, we’re talking about individuals making more than $1.2 million a year.

It’s hard to comprehend those kind of numbers. One percent of people getting twenty percent of the income? It’s worse when you realize that’s only income, not wealth. As of 2007, ten percent of the U.S. population held eighty percent of all financial assets.

I think most of us automatically think of the richest people in America as abstractions. We’ll only see their faces if we see their photos in Forbes. But what if these financial elite are our neighbors? How many of the “richest of the rich” live in Lancaster County?

In my research so far, it’s impossible to tell. There’s really only one definitive statistic: at least five thousand Lancaster County households are among the richest five percent of American households, in terms of income.

The latest research on actual wealth (as opposed to just income) to come from the U.S. Census Bureau is dated 2004, and even then the numbers are only broken down to the state level, not into counties. We know that in 2004, there were 86,000 individuals in Pennsylvania with more than $1.5 million in financial assets. If those individuals were evenly distributed throughout the state population, in 2004 there would have been 3,464 of them in Lancaster County. Further, if we want to consider only individuals worth more than $20 million, in 2004 there would have been seventy-six such individuals in Lancaster County.

Does anyone have any better data on these questions? If not, do my very rough guesses pass the “sniff test” for you? Are there thousands of multimillionaires among the half-million residents of Lancaster County?