While sorting surplus furniture recently, I found my husband's old violin. It hasn't been played for 30 years but the instrument and its battered case has accompanied us on every house move because it has sentimental value and "might be worth something someday".
My husband bought the violin from his 80-year-old music teacher who played it as a child. While not a Stradivarius, it is nevertheless a quality violin and, according to a paper on the value of collectibles, musical instruments have appreciated at an average annual real rate of 2.4-2.8 per cent since 1900.
Elroy Dimson and Christophe Spaenjers published a paper in 2013 assessing the long-term financial returns from high-quality collectible assets over the period 1900-2012.
Their paper concluded collectibles have enjoyed higher average returns than government bonds, bank bills and gold. Equities - shares in public companies - achieved best returns over the long-term, albeit with heightened risk.
The authors considered the long-run returns on art, stamps and musical instruments (violins) because historical price data was available and they are man-made and durable objects that do not diminish with consumption.
Dimson and Spaenjers noted, while some collectibles had earned a respectable financial return, the "psychic return" of holding collectibles is more substantial. That is, pleasure is ultimately what collectibles are all about and investors are willing to forego monetary gains for emotional gains.
A table from their report has some surprising findings and shows the dispersion of annual returns - the lowest and highest recorded for different 'emotional' and financial assets - is wide.
Of course, data based on averages is fraught with danger.
Not all collectibles are created equal; according to The Economist, an estimated 5 per cent of fine wines sold at auction are not what they claim to be (bottles are re-labelled and empty bottles are sometimes refilled with cheaper wine).
The investment return trends can vary substantially across different types of collectibles and time frames.
Tastes can change and collectibles previously disregarded can become priceless as collectors chase scarce assets. At times, the volatility in the price of stamp and art investments is not much different from that of equity investments.
Then there's the risk of forgeries and fraud; the illiquidity of collectibles, some of which can take years to sell; the cost of storage and insurance and the transaction costs - with auction houses sometimes taking a substantial cut of the selling price as commission.
According to one financial adviser, the price of collectibles roughly tends to reflect the global growth in GDP per capita. As more people have more money, the standard of living increases and the price of collectibles increases accordingly.
I guess, if you believe global growth is on an upwards trend, you could consider collectibles as an emotional asset to diversify your financial assets.
Or you can just enjoy the pleasure of owning rare, quality real assets and lug them around with you every time you move...