As long as I've lived in Tokyo, I've wondered why the city's public transportation system, maybe the best in the world, doesn't operate round the clock. One of the explanations I've heard is that taxi companies have successfully campaigned against any extension of train and bus services past midnight.

It's an explanation I've never really bought, but the recent scandal involving cabbies doing favors for bureaucrats has made me rethink the matter. Maybe it's not the taxi companies who have lobbied against 24-hour public transportation, but rather civil servants. If the trains ran all the time, then bureaucrats would have to use them after midnight, and what's the point of being a bureaucrat if you can't have perks like free late-night taxi rides home?

The scandal came to light last month following questions brought up by Democratic Party of Japan lawmaker Akira Nagatsuma, which eventually led to a government investigation that found more than 1,400 civil servants had accepted cash, alcoholic beverages and even bags of rice from taxi drivers in exchange for patronage. The drivers were private operators who received calls on their cell phones from bureaucrats after 12:30 a.m., at which point they can charge the government for taxi rides home, regardless of where they live. If he lives in a distant suburb, the fare can be as much as ¥30,000.