With rising inflation in recent months, stock market investors have been using long-held street wisdom to find hedges, or protection, in commodities, REITs or real estate investment trusts, as well as stocks and equity mutual funds. But while those asset classes provide hedges against energy inflation, they do not offer protection against core inflation, according to a new research paper by experts at Wharton and the University of Hong Kong titled “Getting to the Core: Inflation Risks Within and Across Asset Classes.”
“The key takeaway from our research is that you have to look at what is known as core inflation separately, excluding food and energy items,” said Wharton finance professor Nikolai Roussanov, who co-authored the paper with Xiang Fang and Yang Liu, both assistant professors of finance at the University of Hong Kong. “A lot of the discussion in the popular press on different asset classes in their relation to inflation tend to miss this distinction.”
Core inflation tracks prices of goods and services including shelter, household furnishings and operations, apparel, transportation, medical care and recreation. The indexes for core inflation, along with those for food and energy inflation, make up the consumer price index, or headline inflation. The consumer price index for urban consumers in June 2021 rose 5.4% (before seasonal adjustments), representing the largest 12-month increase in 13 years, according to the latest labor department report. Within that, core inflation rose 4.5%, the largest 12-month increase since November 1991, and energy inflation rose 24.5%; the food index rose 2.4%.
“[Conventional wisdom that] commodity futures, for example, are good protection against inflation because commodity prices will go up is not necessarily true,” said Roussanov. Commodity futures do provide a hedge against energy inflation, “but energy is not always the important component of inflation,” he added. “It just so happened that in the last 20 years, inflation has been subdued overall and energy being its most volatile part really kind of stood out. A lot of movement of inflation has been obscured by high energy prices, oil in particular being the most powerful.”
Key Findings
“We argue that decomposing inflation into core and non-core components (with a particular focus on energy) is important as it sheds new light on the nature of inflation risks,” the paper’s authors stated. “First, core and energy inflation have sharply different statistical and economic properties. Second, inflation-hedging properties of conventional ‘real assets,’ such as stocks, currencies, and commodity futures, are largely confined to energy inflation, while they provide almost no protection against core inflation risk. Third, core inflation carries a significantly negative price of risk, while the risk price associated with energy inflation is in most cases indistinguishable from zero.”
In their study, the authors examined returns in seven major asset classes between 1963 and 2019: U.S. stocks, Treasury notes/bonds, agency bonds, corporate bonds, currencies, commodity futures, and REITs. The data had varying starting points between 1963 (for stocks and treasuries) and 1983 (for energy).
These were their key findings:

- The conventional wisdom that stocks, currencies and commodity futures are real assets is incomplete: They only hedge against energy inflation. A long position in none of these seven asset classes can hedge against the core inflation.
- The cost of hedging against inflation – or the price of these inflation risks – of headline and energy inflation are indistinguishable from zero. However, core inflation carries a sizable negative price of risk. In other words, insuring your portfolio against core inflation is potentially costly due to foregone returns.
- Among commodities, precious metals, especially gold, are the most well-accepted assets to preserve value. Gold and platinum have positive core inflation betas (volatility and therefore risk) that are statistically indistinguishable from zero and they strongly hedge against energy inflation. These precious metal futures have relatively low returns and high volatility, so their ability to protect against core inflation risk is far from assured.