Columnist: Several recent studies show, and insurance statistics confirm, that more pedestrians are killed every year in North American cities when crossing with the light than when crossing against it. Crossing against the light in North American cities is ttherefore less dangerous than crossing with the light. The columnist's reasoning is most vulnerable to criticism on the grounds that it ['ignores possible differences in the frequency of the two actions whose risk is being assessed', 'presumes, without providing justification, that because two things are correlated there must be a causal relationship between them', 'does not adequately consider the possibility that a correlation between two events may be explained by a common cause', 'relies on sources that are likely to be biased in their reporting']