Timber as an Asset Class: If a Tree Falls in the Forest, Should you Buy It?

“If the sun shines and it rains, the trees grow about on schedule,” wrote Jeremy Grantham, chairman of Boston-based investment firm Grantham Mayo Van Otterloo, in his quarterly newsletter in April 2007. Back then, as the housing bubble neared bursting and the S&P 500 stock index approached its post-9/11 high of 1,562, timber was one of the veteran investor's favorite picks because of its safety, high real returns and history of rising during all great equity bear markets.

Three years later, as equity markets face another correction on the heels of a year-long run-up, timber is still one of Grantham's favorite investments, alongside high-quality stocks and emerging markets. During an address at last month's Ira Sohn Investment Research Conference in New York, the GMO chairman said he expects timber to earn 6 percent annually over the next seven years.

Grantham’s enthusiasm for timber, however, may be excessive, despite the fact that, on the surface, historical data seems to support Grantham's optimism. Between 1987 and 2009, the most common measure of the performance of timber as an asset class – the National Council of Real Estate Investment Fiduciaries (NCREIF) Timberland Index, which tracks a large pool of individual timber properties acquired in the private market for investment purposes only – earned a compounded annual return of more than 14 percent. The S&P 500, by comparison, has returned about 9.4 percent in the same period.

Timber also has a history of uncorrelated returns. The correlation of the NCREIF Timberland Index with the S&P 500 since 1987 has been approximately 35 percent, while the correlation of the timber index with the Barclay's Aggregate Bond Index has been just 15 percent. The correlation between the timberland index and the consumer price index during the same period has been 45 percent, suggesting that timber has been a good long-term inflation hedge.

Despite its impressive history, however, we are unconvinced advisors should overweight timber as an asset class. There is no "pure" timber investment with a long track record that is accessible to non-institutional investors, and many wood and paper products face a grim long-term economic outlook. Moreover, timberland's status as a real estate investment in a post-bubble economy is also cause for caution. Indeed, the outlook for timber investments is so murky that many potential timberland investors may be better off seeking more traditional sources of income or uncorrelated returns, such as bonds.

Before exploring our reasons for caution, let’s look at the timber-related investment vehicles available to advisors and their clients.