you may not know it, but there are fascinating secrets buried in our garbage. about our money, about our economy, about how well our country is doing. our trash could be an indication of how our economy is doing, how the global economy, even, is doing. my colleague at the washington post recently pointed out a trashy chart from economist michael mcdonagh. he has worked out the trash to gdp indicator. that's gross domestic product. it shows the u.s. gdp growth tracks the rail cars of garbage tracked to the landfills. it's an 82.4% statistical correlation with the gdp growth since 2001. compare that to 73% for lumber loads, 72% for petroleum, and 79% for food. as mcdonagh recently explained