The world’s three largest economies are the US, China, and Japan. If you knew they had the following growth rates – +16%, +2.7%, and -3.6% — you’d probably be fairly confident in matching the economy to its growth. And the answer is: the US at +16%, Japan at +2.7%, and China at -3.6%.

How can this be? Credit Suisse releases an annual private wealth report. It compiles private wealth in current terms (no inflation adjustment) at the mid-year point.

At mid-2014, American private wealth stood at $83.7 trillion. The second highest national figure belonged to Japan at $23.2 trillion, less than one-third of the American total. China was third at $21.4 trillion. Using Credit Suisse figures for mid-2013, the US saw rapid growth, Japan modest growth, and China a contraction.

Now the acknowledgements. First, Credit Suisse doesn’t publish explicit on-year growth rates, possibly because fluctuations for a single country can be sharp and misleading as to the country’s longer-term performance. Looking back to 2000, China’s wealth record is clearly superior to Japan’s.

Second, these calculations are difficult cross-nationally. The Federal Reserve publishes a series on American net household wealth that puts the value at close to $80 trillion in mid-2014 (adjustment is for non-profits), reinforcing the Credit Suisse figure. But determining the equivalent number for China is much harder, due essentially to government distortions of the economy.

Most important in terms of substance, this is just private wealth. There’s also public wealth.

In the US, high federal debt means net public wealth is negative. The same is true for Japan. China also has serious debt problems but the state owns so much in the way of assets that net public wealth is almost surely positive and fairly large.

So Credit Suisse’s $62 trillion American private wealth advantage over China is an exaggeration. The true gap between the two countries is more like $42 trillion.

The trend may also be somewhat misleading. According to the Fed, the growth of net private US wealth from mid-2013 to mid-2014 is 10.4%, not 16%.

Inexact calculations for China mean private Chinese wealth may not have declined from mid-2013 to mid-2014. At the same time, rising Chinese debt is mostly due to public enterprises, which means net public wealth may have declined.

While Credit Suisse’s measurements of private wealth are incomplete and inexact, they are real-world figures. Individuals, companies, and governments hold or utilize wealth, and change their economic fortunes by doing so. The distribution of wealth matters a great deal.

In contrast, gross domestic product adjusted for purchasing power parity (GDP PPP) is a book-keeping device modified in a way that makes it less applicable to the real world, whose distribution is of no interest to anyone. Good luck buying a car, building a solar plant, or funding a military expansion with a share of GDP PPP.

The International Monetary Fund says China may have already passed the US in GDP PPP. Credit Suisse implies the US is roughly $40 trillion ahead in wealth and the gap just widened. Is there a patriot in either country who would hand over $40 trillion (or half that, or a quarter of that) to be tops in GDP PPP?

Properly measured, the US economy is much bigger than China’s and may even be pulling away.

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