James Grant examines a crucial problem with Treasury Inflation Protected Securities: they don’t necessarily protect against inflation!
Inflation, after all, is a matter of dollars–an increase in the supply of money not offset by an increase in the demand for money. People will say, “Inflation is too much money chasing too few goods,” but there’s a lot besides goods that too much money can chase: stocks, bonds, houses, foreign currencies, etc. The cause of inflation is always the same, yet the symptoms are ever changing, and TIPS protect against only one set of symptoms. link