Christmas is the season to find out which sports are up and which are in trouble. Shoppers will exit European and American malls this weekend laden with sports kit. The US market for it is worth an estimated $46bn (£24bn) a year.
Much of it, admittedly, is bought to wear in the office. But the shopping bags do in part reveal which games people play. So do surveys and the testimonies of sportswear executives. It turns out that some traditional sports are fading. This is bad news for society.
Europe and the US being different universes, we have to treat their sports markets separately. The most privileged observer of European trends is possibly Herbert Hainer, chairman and chief executive of Adidas-Salomon. "The growth rates of football are unceasing," the Bavarian told me while eating prawns at last month's International Football Arena conference in Zurich. "Twenty years ago we had the hooligan scene. Now the stands are full, except at Juventus [Turin] maybe. Football has never been more popular than today."
More Europeans are playing soccer but Hainer denies this means that they are deserting other ball games. Yet Adidas' recent presentation of its European strategy to investors suggested that people are. "Football and lifestyle drive consumer demand," stated one slide. Another read: "Football becomes 'super sport'." The only other sport even mentioned on the slides was running. Role models are crucial, and European kids want to be David Beckham, not some middle-income volleyball nerd.
I met Hans Faber, spokesman of Nike Europe, in the company's headquarters in the Netherlands, a sort of adult playpen where employees spend much of their lives playing sport. Faber confirmed that Europeans are deserting most team games and tennis. Instead, they prefer activities they can do alone, without having to make arrangements with other people: yoga, or going to the gym. Faber said: "The further north you go in Europe, the more developed are these fitness sports. So you can forecast trends: if you look at what's happening in a gym in Stockholm or Oslo, nine times out of 10 you can predict what will come in other European countries."
In the US, team games are fading even faster. Each year the National Sporting Goods Association asks Americans which sports they play. It found that in 2003 every team sport except tackle football - a version of American football - lost players. Basketball, the most popular team game - played by 28m Americans last year - declined by 4 per cent. Soccer suffered the worst fall, plummeting 19 per cent to just 11m players, making it the country's fourth team game behind baseball and softball.
But all ball games are niche compared with America's five favourite sporting pursuits: walking for exercise, camping, exercising with equipment, swimming and bowling. It's a sobering thought that nearly three times as many Americans drive for pleasure as play outdoor team sports. The country is ceasing to play the games it watches.
Just as Europeans and Americans inhabit different universes, so do rich and poor Americans. The rich ones play more sport. Nearly 80 per cent of people earning more than $80,000 do some kind of exercise, according to polls by the Leisure Trends Group. But of black Americans - who are over-represented in professional sports - only 37 per cent play sport.
Each income bracket has its own sporting penchants. An NSGA survey this autumn revealed that people earning more than $100,000 a year are more than three times as likely as other Americans to buy elliptical cross trainers (a species of exercise machine) and golf clubs. Golf, various reports show, remains most popular among rich easterners despite its purported democratisation. In fact the sport seems to have ceased trickling down. Fewer new courses are opening in the US, and fewer rounds are being played.
Poorer Americans have their own favourite sports. Those earning $25,000 to $34,999 are twice as likely as the rest to buy billiard or pool cues. People making between $15,000 and $24,999 prefer guns: air rifles, pistols and shotguns. The very poorest Americans don't buy much of anything.
All these trends recall the legendary article "Bowling Alone", published in 1995, by Harvard professor Robert Putnam. It explained that American society was atomising: people no longer met in monthly bridge clubs, or at the League of Women Voters, or had picnics together. They were even bowling alone.
Both in Europe and the US, things have only got worse since. Soccer in Europe aside, this is the era of playing alone.