Perceived Risk vs. Actual Risk
We often see debates about whether or not volatility of returns is a good measure of risk. This debate is related to what I think is a bigger issue: the difference between perceived risk and actual risk. Perceived risk is influenced by observations and “dollar bias,” but actual risk comes from the full range of what might happen and its influence on buying power. Dollar bias and buying power In some contexts we forget about inflation and view dollars as constant over time. For example, we tend to focus on nominal returns and think that it’s okay to spend gains as long as we leave the principal intact. But the principal will erode with inflation if we spend all the nominal gains. Another context where we see this bias is with mortgages. We can calculate that with a 30-year $400,000 mortgage at 4%, the first year’s payments will only reduce the principal by about $7000. But even with only 2% inflation, the buying power of the principal will erode by abo...