All sorts of unexpected causal chains in the news recently. Higher oil prices mean Americans driving fewer miles, which means revenue shortfalls for highways but also a fall in the number of traffic fatalities. Threatened and actual home foreclosures mean some people wanting divorces can't afford them, while their swimming pools, the filters turned off, are breeding grounds for mosquitoes (some of whom, in San Diego, may carry West Nile Virus). Job losses are leading some people to marry to qualify for insurance through their spouses. And abroad, chemical factory shut-downs in Beijing to improve air quality for the Olympics have led to shortfalls for Indian pharmaceutical companies...