From The Economist:
Shares and shibboleths
IF THERE is a sacred belief among investors, it is that equities are the best asset for the long run. Buy a diversified portfolio, be patient and rewards will come. Holding cash or government bonds may offer safety in the short term but leaves the investor at risk from inflation over longer periods.*As I said in last month's "Foreign exchange: Why Does the Carry Trade Work?"
Such beliefs sit oddly with the performance of the Tokyo stockmarket, which peaked at the end of 1989 and is still 75% below its high. Over the 30 years ending in 2010, a “long run” by any standards, American equities beat government bonds by less than a percentage point a year.
In the developed world, the period since the turn of the millennium has been a particular disappointment. Since the end of 1999 the return on American equities has been 7.6 percentage points a year lower than that on government bonds (see chart 1). That has left many corporate and public pension funds in deficit and many people with private pensions facing a delayed, or poorer, retirement. Understanding why equities have let investors down over the past decade will help them work out what to expect in the future.
The long-term faith in equities is based on the theory that investors should be rewarded for the riskiness of shares with a higher return, known as the “equity risk premium” (ERP). That risk comes in two forms. The first is that shareholders get paid only when other claimants on a company’s cashflow, such as workers, the taxman and creditors, have received their due. Profits and dividends are thus highly variable and can disappear altogether when times get tough. The second risk is that share prices are volatile, more so than bond prices. Since 1926 there have been seven calendar years when American equity investors have suffered a loss of more than 20%; investors in Treasuries have suffered no such calamitous years.
The big question, however, is how large that extra return should be. Here it is important to distinguish between the extra return investors actually achieved for holding equities (what could be called the ex post number) and the return they expected to achieve when they bought them (the ex ante figure). Academics started to focus on this problem in the mid-1980s when a paper by Rajnish Mehra and Edward Prescott indicated that the ex post return of American equity investors had been remarkably high, at around seven percentage points a year. It seems unlikely that investors expected to do so well.
Premium puzzle
There are a number of possible explanations for these very high ex post returns. One is survivorship bias in the numbers. America, which is the benchmark for ERP measurements, turned out to be the most successful economy of the 20th century, but it might not have been. Before the first world war investors doubtless had high hopes for Argentina, China or Russia—only to be disappointed.
Elroy Dimson, Paul Marsh and Mike Staunton of the London Business School (LBS) have analysed the data for 19 countries from 1900 to 2011 and found that the ERP relative to Treasury bills (short-term government debt) ranged from just over two-and-a-half percentage points a year in Denmark to six-and-a-half points in Australia. They found a premium for America of five percentage points....MORE
The DMS trio impacted my thinking eight years ago with their paper "Irrational Optimism".
Previously on the Risk Premium Channel:
What Risk Premium Is “Normal”?
A Really Smart Guy On Stocks, Bonds and Expected Returns
"The Real Role of Dividends in Building Wealth" (Clearing Up Muddled Thinking about Dividends)
The Equity Risk Premium: "Using Garbage to Measure Consumption"
Equity Risk Premium: "Why the market’s rate of return—and your nest egg—may never recover"
And many more, use the search blog box
