Chen's finding is that if you divide up a large number of the world's languages into those that require a grammatical marker for future time and those that don't, you see an interesting correlation: speakers of languages that force grammatical marking of the future have amassed a smaller retirement nest egg, smoke more, exercise less, and are more likely to be obese. Why would this be? The claim is that a sharp grammatical division between the present and future encourages people to conceive of the future as somehow dramatically different from the present, making it easier to put off behaviors that benefit your future self rather than your present self.
Chen's paper has yet to be accepted for publication, but it's already generated a lot of press of the sort that's festooned with flashing lights. For example, in his popular blog, Andrew Sullivan headlined the story with the pronouncement “Why Greeks Haven’t Saved for a Rainy Day”. A facetious headline, no doubt. But before someone suggests that the European Union should make bailouts of troubled countries contingent on their retiring their grammatical tense markers, it's worth taking a reality check about the ways in which language can or can't affect the thoughts and behaviors of its speakers.