I like to think of myself as a light viewer, but in truth I watch 30 to 90 minutes a night plus at least that much again of children's programs in the background each morning.
The typical Australian is said to watch two to three hours a day. Added up over a lifetime, that means someone who lives to 75 may have watched TV for nine years. The only things we do more of are work and sleeping.
So it's odd that economists haven't much studied TV viewing until now. When they have, they have found that we enjoy it. Most recently the Nobel Prize winner Daniel Kahneman asked 1000 women to record how they felt at each moment of the day. They felt their best when having sex, socialising, eating and watching TV...
They enjoyed TV more than they did talking to their spouse, shopping or caring for their children.
Now a team from the University of Zurich is suggesting that Kahneman and others have been looking at only half the picture. In a paper entitled Does Watching TV Make Us Happy? Bruno Frey and his colleagues argue that it is not enough merely to ask people how they feel at the exact moment when they are watching TV. It is also necessary to ask how people who watch a lot of TV generally feel.
They say that drug addicts feel great at the exact moment they are getting their fix, but they generally feel awful.
The team had access to data from a European survey in which 42,000 people were asked: "All things considered, how satisfied are you with your life as a whole nowadays?" They were also asked how much TV they watched. The team found that the people most satisfied with their lives were those who watched TV the least.
The effect was large. One of the most important predictors of happiness (for men) is whether they are married. The effect of not watching much television is about one third as big.
The team was left with a paradox. Watching TV made people feel good while they were doing it, but seemed to make them less satisfied overall.
Other activities affect us in the same sort of way. One is smoking. Cigarettes hurt smokers, but they do so slowly. Immediately, they offer relaxation - which becomes addictive.
Bruno Frey could see how television might act like that. It offers an immediate benefit - relaxation, with the costs not apparent until later. Those costs include tiredness, weak social relationships and insufficient attention to study and careers.
People who don't care about the future or who lack self-control will watch more TV than they should, and will be less happy as a result.
Opinion polls suggest that this is the case for many Americans. Forty per cent of US adults and 70 per cent of teenagers say they spend too much time watching TV.
But there is another possibility which Frey and his team have not been able to rule out completely. It's that rather than excessive TV use making people unhappy, people who are already unhappy may choose to watch a lot of TV.
Frey thinks this is not the case, and he designed a test to back up his opinion. He says if he is right about heavy TV viewing causing unhappiness, it won't do it to everyone.
The only people seriously harmed by heavy viewing will be those who have other things they can usefully do with their time. (Economists call them people with "high opportunity costs" of time.)
They include the self-employed, senior managers and people in professions where the work never ends. For them, lost time matters.
By contrast, pensioners and the unemployed (with low opportunity costs of time) shouldn't be that much harmed by the hours taken up watching TV - they might even welcome them.
Frey has gone back to the European data and found exactly that pattern. Watching TV for more than 1½ hours a day doesn't appear to hurt pensioners and the unemployed, but it makes a big dent in the happiness of the professionals who do it. Denied time in which they know they could be really achieving things, they feel perpetually unsatisfied.
TV appears to play with our minds in other ways as well.
The European survey asked people about their anxieties. One question asked: "How do you feel about your household's income these days?"
Another asked: "How important is it for you to be rich?"
Frey found that heavy TV viewers were both more anxious and more greedy than were light viewers on the same incomes. They were also more scared about the outside world.
Other questions asked whether people could generally be trusted, and whether it was safe to walk outside at night.
On both counts heavy viewers were more frightened.
Television viewing is by far our biggest leisure-time activity. And it's not all bad. (I happen to work in television.) But until now discussion of its impact has moved little beyond debates about whether or not it makes us violent. Its biggest crime may be to steal our time.