Economics of sleep: Snoozing geysers WEALTH clearly parts company with health if it makes you nervier, boozier or fatter. But finding data to prove the links is tricky. A new paper* for America's National Bureau of Economic Research by Tinna Laufey Asgeirsdottir of the University of Iceland and her colleagues has given some unusually precise answers. Until autumn 2008 Iceland's economy was happily frothing with borrowed money. Bank deposits were 14 times larger than the country's GDP. In the space of a few weeks it collapsed. Iceland defaulted and nationalised its banks; the currency plunged by 36%. Businesses collapsed and many households lost their savings. GDP fell from peak to trough by 15%. Incomes plunged and anxiety levels soared. That was sad for Icelanders but nice for economists. It gave a useful and rare example of the effects of a big, sharp and general economic shock. What the authors term their "clean and well-stocked laboratory" also includes detailed information on the health and lifestyle of a representative sample of 9,807 Icelanders, surveyed in 2007 and again in 2009. The study measured 11 forms of behaviour, including the use of alcohol, tobacco, indoor tanning, sugary drinks and snacks; and (on the positive side) sleep, exercise and fresh food. One finding (see chart) is that all unhealthy forms of behaviour fell, especially among those of working age. That may reflect falling income levels (alcohol is notoriously pricey in Iceland). People ate less confectionery and fast food (though that also may reflect what the authors call "extreme supply-side changes," as McDonald's closed its Icelandic branches). But their diets worsened overall (Iceland produces little fresh food, and imports became costly). On the plus side, the incidence of marriage rose. Ms Asgeirsdottir herself wed her long-term partner: for love, she stresses. Icelanders worked fewer hours. Their worries did not keep them awake - time spent asleep increased, particularly for men. That may reflect the opportunity cost: in a boom skimping on sleep may mean you can earn more (though, like many things that seem a good idea at the time, the true costs may show up later). Now economists are licking their lips at the feast of new data that will doubtless emerge from woes elsewhere in Europe.