The first trillionaire

Annie Lowrey hypothesizes as to when he (or, indeed, she) may arrive:

The answer depends on variables including inflation, tax rates, and overall economic growth. In a first case, let's assume that our hypothetical trillionaire is actually only as rich as today's richest American, Bill Gates, whose estimated net worth is $56 billion. Since inflation slowly erodes the value of the dollar, it will be easier and easier to hit the trillion-dollar mark as time goes on. (We were all once Zimbabwean trillionaires, after all.) If the United States averages 3 percent annual inflation, and the richest American's fortunes keep up with Gates', America would have a trillionaire in 98 years. But now let's assume that the richest American's fortune not only matches the rate of inflation, but outpaces it by, say, an additional 3 percent a year. At that rate, we should have a trillionaire in 50 years.