Looting abandoned homes just ain’t the fun it used to be.

Stripping foreclosed homes of their copper pipes became big business when commodity prices soared, driven by easy credit, a weak dollar and a robust global economy. Since the summer, however, the prices of base metals have fallen precipitously, with copper's decline being the most dramatic.

Analysts don’t expect the trend to reverse any time soon. Despite a massive economic stimulus package from China, the world’s largest copper purchaser, some experts believe the metal could slide as much as 40% further.

Bloomberg reports global inventories have risen twofold in the past 4 months, as auto sales have slumped, new home construction has all but ground to a halt, and fears about a worldwide economic slowdown are becoming reality. Bigger stockpiles, coupled with faltering demand has led to a collapse in commpodity prices: The S&P GSCI Index, which tracks 24 raw materials, has fallen by more than half since July.

Minyanville’s Ryan Krueger regards copper as a proxy for global productivity. Unlike gold or silver, copper is unaffected by speculation, since demand for it is purely pragmatic: It serves as the essential material for construction of all types.

Miners like Freeport MacMoran (FCX) and BHP Billiton (BHP) have been hauling the stuff out of the ground at record rates in the past few years in order to keep up with skyrocketing demand. Shares soared, reaping big profits for investors.

Since its low in 2000, Freeport rose almost 1800% to its high just a few months ago. Shares have since come back to earth: Freeport and BHP are down 81% and 66%, respectively.

According to the Wall Street Journal, miners are now racing to cut production in reaction to slumping demand. US Steel (X) will lay off 2% of its workforce, as mining companies around the world are forced to cut overhead to stay alive.

Meanwhile, construction costs are tumbling, fueling fears about central bankers’ worst nightmare: Deflation. It seems like yesterday that Federal Reserve Chairman Ben Bernanke and his ilk were scared stiff about inflation; rising prices have already sparked riots in developing countries around the world.

As Professor Kevin Depew put it last week,

"The argument against deflation and inflation is both academic and political. Present economic elites benefit from inflation and suffer terribly in deflation. Therefore, there is great incentive for the small minority -- the 2-3% of wealthy who control the vast majority of assets in this country -- to continue to press government and the Fed to maintain the present course of inflation over deflation."

Deleveraging is lowering the value of all assets, from stocks to bonds to houses to steel. Those whose wealth is tied up in these commodities are scrambling to halt the accelerating evaporation of their value.

After years of watching the rising tide lift their boats, they now find themselves foundering on the shore - which is already littered with those who never set sail in the first place.