I have not subjected my hypothesis to an econometric test, but casual empiricism suggests that when people do put up birthday decorations, they tend to linger for a few days at most and, importantly, go up on the day itself, not in advance.

• 我没有对这个假设进行过经济学验证，但间或获得的一些经验显示，人们的生日装饰往往最多也就保留几天，而且重要的是，要在生日当天装饰，而不是提前。