Economic theory would now predict that taxi drivers make longer days when it is raining because then they make more money per hour.

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"We'd saved money for rainy days, but ... it was raining, " Valles said.

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It all sounds great, but before the sunny days for solar thermal arrive it needs to start raining cash.

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Some days, they (told themselves they) were lucky because it started raining and they allowed themselves to go home early.

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