Oil investors are scratching their heads over the recent drop in oil prices.  For the week, crude oil fell from $101 per barrel to lower than $97 per barrel -- a trend that has pretty much defined the oil market through January. Right now, oil prices are at their lowest since Dec. 16, 2011.

That’s not the best news for oil investors. After all, 2012 was supposed to open with a "bang" -- but recent events are blowing up in oil investors' faces.  Those events were at least partially offset by January’s positive, if misleading, U.S. unemployment numbers.

(The official view from the U.S. Bureau of Labor Statistics is that the economy added 243,000 jobs last month, knocking the unemployment rate down to 8.3%. But the numbers don’t account for 1.4 million Americans giving up and leaving the workforce -- they’re not counted in the government figures.)

That makes a big difference in calculating the jobless numbers. The Financial Times said, “If the same number of people were seeking work today as in 2007, the jobless rate would be 11%.”

So, while oil prices have received a boost from a flawed unemployment number, the larger issues dominating the economy are working against crude oil, and have been steadily knocking prices down since the start of the year.

“(While) payroll numbers will dominate macro-driven trading,” noted Andrey Kryuchenkov , an analyst at VTB Capital in London, who sees oil prices continuing to slide in February, “global demand growth is slowing this year, while developed nations will see contracting consumption,” he told Bloomberg News on Feb. 3, 2012.

What’s driving oil prices downward? There’s no single reason, but plenty of issues that, cobbled together, have fueled a weakness in crude oil prices. Here are some of the reasons at the top of that list.

Low consumption.  U.S. gasoline consumption is off, down to 7.97 million barrels per day. That’s the lowest number in 11 years, says the U.S. Energy Department . Part of the problem is the warm U.S. winter, as demand for heating oil is down significantly, although the Organization of Petroleum Exporting Countries (OPEC) is ramping up oil shipments in anticipation of higher demand in the next three weeks.

OPEC shipped 23.5 million barrels of oil in the four weeks leading up to Feb. 18 -- 1.1% more than a similar time period in January. But January’s sluggishness has carried