Long-term dollar swings and commodities

There have been a number of long-term dollar swings since the beginning of floating exchange rates and we are currently in another potential transition point for a dollar rally. 

The long-term dollar swings have been:

1968-1978 Decline -The Bretton Woods destruction and move to flexible exchange rates

1978-1985 Appreciation -Dollar gain from Volcker period of Fed tightening

1985-1992 Decline -The offset from Volckerism overshoot 

1992-2001 Appreciation - The period of Great Moderation, the tech productivity boom 

2001-2011 Decline - Ascent of emerging markets and EU

2011 - ?     Appreciation - Global decline 

Commodities have done poorly during periods of dollar appreciation and have done well during periods when the dollar has been in decline. A simple explanation is that since most commodities are priced in dollars, there will be a drag on commodity demand when there is a dollar appreciation. 

'68-78 was the period of stagflation and major price hikes in agricultural and energy;

'85-92 was the ascent of energy and agricultural  prices;

'01-'11 was the period of the super cycle. 

The period of dollar ascent matched poor emerging markets and falling commodity prices. The early 80's was the period of Latin American crises. The '92-'01 was a period of the Mexican and Asian crisis. Avoid commodities during a dollar appreciation and crisis period.