From watching cable news or reading too much on the Web, it is easy get the impression that the world as we know it is close to an end: the collapse of the EU, the Iranian and North Korean nuclear question, terrorism, climate change, growing global income disparity. You name the risk, and we seem on a collision course with it. Tomorrow.

But don’t let these risks get in the way of your optimism about the world’s potential for economic growth, America’s potential to grow with it and in investors’ profits from owning stocks of companies positioned to take advantage of risk.

That was Professor Jeremy Siegel’s message during his Lifelong Learning presentation Saturday morning at MBA Reunion: optimism.

On the large screen at the Harold L. Zellerbach Theatre in the Annenberg Center was the chart that helped to make the Russell E. Palmer Professor of Finance so highly renowned in the business world: the real returns after inflation of several asset classes from 1802 to the present. Over that period of time, stocks have been the resounding winner, earning 6.6 percent real returns per year on average. A single dollar used to buy stocks in 1802 would be more than $613,000 today. No other asset class comes close. A dollar in gold purchased in 1802 would be worth $4.27 today.

Siegel pointed to the chart and listed all the calamities that befell the United States and the world during that time: the U.S. Civil War, World War I, World War II, the Cold War and its daily threat of nuclear annihilation, to name a few.

“We had risk all the time. We always had the risks,” Siegel said.

Professor Jeremy Siegel

And sure today, the European Union could seemingly dissolve. Government debts there, here and elsewhere appear to be unsustainable and growing. The American baby boomer generation, 85 million strong, is retiring and isn’t quite sure if we can afford to pay for that.

Yet another important development in the next 20 years could be incredibly positive and powerful, according to Siegel: the rise of the middle class in emerging markets. At present, 1.8 billion people are considered middle class in the world. In 20 years, that number is projected to grow by 2 billion. Middle-class spending power could jump from $23.3 trillion to $55.7 trillion, and that number is conservative, Siegel said. Think of the wealth and opportunity generated when American went through its middle-class transformation after World War II.

“What we’re seeing in Asia is even faster,” Siegel said.

Siegel has seen stocks cheaper than they are now, but he’s never seen stocks cheaper compared with bonds.

So optimists can be expected to join Siegel in investing in “stocks for the long run,” as the title of his singular investment book implores.