“If you own stocks without a hedge, it’s not rational.” So says the world’s most famous student of risk Nassim Nicholas Taleb in a recent interview with Bloomberg as many of the world’s stock markets hover near all-time highs. “It’s like buying a house without insurance,” he explained. “We have tail risks today that we didn’t have before, and every day it gets worse.”

“Tail risks” refer to the possibility of unusual, rare, catastrophic events, often of a nature that cannot be anticipated or even imagined. Such events are frequently dubbed black swans, a term made famous by Taleb’s book called The Black Swan.

So, what is the perceived difference between houses and stocks and what does that tell us about how we judge risks elsewhere in our lives and societies? First, houses. Houses are very expensive consumer items or investments or both, depending who is buying them and why. Taleb’s point is that the value of a house will not track the market if the house burns down.

Every homeowner understands this and buys insurance. In fact, the bank requires insurance if the home has a mortgage. And, that’s because, of course, homes don’t rebuild themselves if they are destroyed.

The companies underlying stock listings, however, are not obliterated by a market crash. Of course, some companies may disappear if the crash is followed by an economic downturn; but the thousands of companies that make up the exchanges do not all evaporate.

Stocks have historically recovered after losses, even extreme losses. So, the hedging Taleb is suggesting is really about timing. Can an investor afford to wait for the rebound before having to cash in? If Taleb’s concerns are borne out in the next few years, many near retirement or already retired may be answering this question.

(The history of stock markets reveals a mixed picture. Some rebounds to previous highs have occurred within months or years. Some have taken decades. The Japanese stock market has yet to revisit the peak of 1989 and currently stands at about half the level of that peak.)

With housing and stocks we have two different kinds of risk, both of which can be hedged so as to prevent a severe loss of net worth. Why do most people only hedge one, namely the home?

Now, most investors diversify their investments. They own some stocks, some bonds, some real estate and perhaps some other investment such as a business they control or an annuity. While diversification, if done properly, can reduce risk, it is not true hedge.

Hedges are designed to go up in value directly in relation to the instrument they are hedging. Owning gold as a hedge against a stock market crash may or may not work. Gold is not a true hedge in this instance and in the last market crash, it plummeted along with stocks. Stock options that necessarily rise in value as stocks sink are a true hedge.

Of course, homeowners insurance does not insure us against a decline in real estate prices. It turns out that one can actually now hedge that risk with the appropriate financial instruments. But few people do that for their family homes. In fact, people rarely envision having to sell their homes for less than they bought them.

It is this one-way bias that links people’s perceptions of both homes and stocks. It is almost inconceivable that any of us might be forced to accept catastrophic losses if only we can hang on long enough. What this view presupposes is that the future will look like the recent past (that is, the last century or so). It will be one of growth, growth, growth. Growth in population. Growth in economic output. Growth in financial wealth. Growth in the energy supplies needed to make all the other growth happen.

It would indeed be a black swan if growth failed to appear or was so stunted that few people obtained any benefits from it. (Has the second scenario already arrived?) But the twin crises of energy depletion and climate change make such a future ever more likely. These crises aren’t hidden and they aren’t cyclical. They are advancing in such a way that the risks of both are not staying neatly tucked under the “tails” of the bell-shaped distribution curve of possible outcomes. Our current actions make them inevitable.

Things could change. Human societies could revolutionize the way they live so as to avert disastrous climate change or fossil fuel depletion (that is, depletion without adequate alternative energy). But, it seems that such a revolution would be more akin to a black swan than any rendezvous with energy or climate Armageddon.

We’ve convinced ourselves as a world society that such outcomes are so unlikely that we are making what amount to token efforts to avert them. Renewable energy is being deployed rapidly, but not rapidly enough to replace the current fossil fuel infrastructure soon enough to prevent a climate catastrophe (and perhaps an energy insufficiency).

There is no insurance policy that will protect us against catastrophic climate change. We cannot get our habitable climate back on any time scale that matters to humans once it’s gone. The insurance policy is us, that is, changes in our behavior and our technology done quickly enough to matter. There is no other hedge that will help us.

Image: The Christmas flood 1717 was the result of a northwesterly storm, which hit the coast area of the Netherlands, Germany and Scandinavia on Christmas night of 1717. In total, approximately 14,000 people drowned.  Copper engraving (1719).   Via Wikimedia Commons.