FYI: There are no conclusive definitions of an asset class or definitive lists of asset classes, but asset allocation depends on how one chooses to define asset classes that collectively form the opportunity set. A company owned by Morningstar called Ibbotson Associates together with PIMCO pulled together some research on the topic that I think is interesting. They present a framework based on three super asset classes:
Regards,
Ted
http://www.etftrends.com/2015/04/indexology-commodities-to-be-or-not-to-be-grown/
Comments
Asset valuation has a direct relationship with the currency it's being valued in. The fluctuation of the purchasing power of world currencies, like ocean waves, can magnify the fluctuation of how fundamentals impact asset value.
A relatively strong currency (US dollar) acts to magnify purchasing power when purchasing deflating commodities assets. While weak currencies that buy these same commodities feels no different than when commodity prices were high and the currency were strong.
Additionally, weak currencies need to be exchanged into stronger (more expensive) currencies prior to settlement. For example, Euros have to be exchanged into US dollars before Europeans can purchase oil. Though, oil may be deflating in price relative to US dollars, Europeans exchanging weak euros into US dollars don't experience the pleasures of "cheap oil."
It seems to me currency should plays a role in this conversation.