It's well known that a major reason why the middle class is in decline is the stagnation of wages, a topic I have covered many times, most recently in What's the Source of Soaring Corporate Profits? Stagnant Wages.

But another often overlooked source of middle class decline is the erosion of middle class wealth. The dynamic behind this long-term trend was indirectly described in The Stock Market Is Like a Fish Tank: the middle class is the majority of fish in the wealth tank that arrive after the gains have been reaped.

In effect, the few who skim most of the financial gain need the middle class to pony up the liquidity and wealth to be skimmed.

In terms of risk, the middle class is always late to the asset class feeding frenzy, meaning that the middle class invests its capital when the opportunities for outsized gains is long-gone and the risk of loss has risen to levels that guarantee declines.

Moving with the majority offers an illusion of low risk. Following the crowd into real estate, tech stocks, tulips, etc. seems like a safe bet because "everybody's making money," but like the fish in the pond, what the middle class is seeing is not "everybody making money" but the relative few who invested early making money and selling to the middle class to reap their outsized gains.

The illusory safety of following the crowd feeds the wealth-destroying dynamic of taking on high risk for either zero gains or huge losses once the asset bubble du jour pops.

The 10 million homeowners who are still underwater (their mortgage debt exceeds the value of their home once selling transaction commissions and fees are subtracted) provide an example of this dynamic. Despite the inflation of an echo-housing bubble (a second bubble in housing valuations, driven by cash buyers), around 25% of all homeowners have no home equity or too little home equity to buy another house should they sell their current home.

Another significant percentage of middle-class homeowners is trapped in their current house by the enormity of their debt and their stagnant income: they no longer qualify for a mortgage or refinance.

There are now three asset bubbles to choose from: housing, stocks and bonds. In each asset class, the majority is convinced that there can only be further gains from here. Risk is seen as low and complacency is high, the classic signs that the outsized gains have already been reaped and all that's left in the tank to divvy up are the risks and losses.

No wonder the wealth of the middle class keeps declining: every temporary gain from joining the investing feeding frenzy sets up staggering losses when the bubble du jour pops and there's nobody left to sell to.

Meanwhile, those who bought early have long since sold out and are now buying outlier assets that are viewed as "risky" by the majority who happily accept high risk in return for temporary gains in the asset bubble of the day, guaranteeing a steady progression of losses and an erosion of real wealth.

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