IN THE debate over alcohol advertising, France is often advanced as an example because of the country's tough legislation that strictly limits the rights of drinks producers. Supporters of a ban on liquor adverts point to a steady decrease in alcohol consumption in France since the Loi Evin came into effect 20 years ago. The picture is more complicated than that, and the evidence is extremely patchy.

France tightened its controls in 1991 to fill a legal void everyone agreed was no longer viable. Named after the health minister of the day, the Loi Evin is a characteristically French response to the question of how to resolve a social issue. While other European countries such as the UK and Germany created systems of self-regulation - with standards agencies that monitor what is aired - France chose to enshrine exactly what is permitted, and what is not, inside a modification to its legal Code of Public Health.

The basis of the law is that only what is specifically mentioned is permitted. Everything else is banned. Thus alcohol advertising is authorised in the written press, on the radio at defined times and on billboards. It is prohibited on TV, in cinemas and in sports grounds. When the law was enacted, the internet did not exist so, in principle, the web was also off limits. However, that changed in 2009 and now websites can carry alcohol ads as long as they require browsers first to attest that they are over 18.

The limit on media access is one of the two axes of the law. More important is the other, which sets out permitted content. Essentially alcohol advertisements can convey only the "objective qualities" of a drink. These characteristics were originally defined as name, place of origin, ingredients, means of manufacture and mode of consumption. But six years ago, the French wine industry - suffering from a chronic decline in domestic sales - complained that the rules made it impossible to promote the virtues of un bon vin franc ais. As a result, it is now also permitted to evoke a drink's more aesthetic qualities, such as colour, taste and smell.

Of course the line between what is authorised and unauthorised is impossible to define, so millions of euros have been spent on lawyers' fees over the years. Gradually, a body of case law has built up, allowing advertisers to know more or less what they can get away with. Essentially, it is not permissible to show anything that extols a beverage, or can be interpreted as an encouragement to drink it. An ad for Scotch whisky, for example, can show a worker in a distillery (means of manufacture) but not a generic Scotsman in a kilt. Handsome barmen and pretty barmaids are taboo, as is anything resembling a party.

Recently, Kronenberg was prevented from displaying the image of a can of beer draped in a feather boa (evocation of fun). Chivas brandy was not allowed to show an old book and a pair of reading glasses, because such items - intended to create a mood of age and erudition - had no bearing on the origins of the actual drink. Another case before the courts concerns Ricard pastis. The slogan on its latest ad reads "Un Ricard, des rencontres", which means "A Ricard, some encounters or meetings". This was disallowed because it suggested that if you drank Ricard, you would have a more interesting social life. The case is now under appeal.

I n this restricted environment, sports sponsorship has no place at all. The European club-rugby trophy, the Heineken Cup, is referred to in France as the H Cup. When the Welsh national side plays in Paris, they have to replace their regular shirts, which bear the logo of their Brains beer company sponsor. The only French club with a drinks sponsor - a local wine company - is the rugby league side, the Catalan Dragons.

They get away with it because they play in the English Super League.

Defenders of the Loi Evin say the law has helped set the moral framework in which the debate over alcohol can take place. Because there is less incitement to consume, there is less legitimisation. It is perfectly true that advertisements for drinks in France are more neutral and less glamorous than in other European countries. But what evidence is there that the tougher rules have had any effect on people's habits?

Studies show that there has been a 20% decline in alcohol consumption in France since the law came took effect. In 1990, 15,4 litres of pure alcohol were sold per person aged over 15; in 2009 that had fallen to 12,3 litres. But the graphs also show two things: first, that this downward trend began many years before, as early as 1960; and, second, that it is entirely accounted for by the changing cultural attitude to wine. Essentially, the French have stopped treating wine as a permanent accompaniment at meal times, so over 50 years, the decline in overall alcohol consumption has been exactly mirrored -not to say caused - by a fall in sales of cheap vin de table. Meanwhile the sales of beers and spirits have remained constant.

Supporters of Evin also point to the steep decline in the number of road deaths. In 1991, about 10000 people died in road accidents, and this fell to 3992 last year. Undoubtedly changing drinking habits did play a part in this, but a far greater factor was the start of zero-tolerance policing in 2002 and the introduction of speed radars.

But the most important argument in the alcohol debate centres on the new ways in which French people consume alcoholic drinks today. The French drink alcohol less regularly but, when they do drink, they drink more. More worrying , this trend is particularly evident among the young.

A 2007 study (the latest available) published by the French Observatory for Drugs and Addictions found that nine out of 10 16-year-olds have tried alcohol, and 13% drink regularly. About half have experienced drunkenness and 40% have had five glasses or more at a time at least once in the last month. Overall, there is mounting evidence that young people are moving towards patterns of consumption familiar in other European countries. They drink outside the home, mainly at week ends and often with the intention to get drunk. Comparisons in the media with the "binge-drinking" culture of the UK and Ireland tend to be exaggerated, but this is the direction in which things are moving. This summer, a number of towns and cities have banned night sales of alcohol because of the risks of rowdiness. Hospitals report record numbers of young people admitted in alcoholic stupor.

All this suggests that the social factors influencing drinking habits are far more powerful than the presence or otherwise of certain kinds of advertisement. This is conceded by Evin's defenders, though they still say the law makes a difference.

But others are more critical. According to Gilles Buis, a media lawyer who advises drinks companies on how to stay onside in their advertising, the Loi Evin may even have had the perverse effect of focusing manufacturers' attention on the young.

Fifty years ago, France had far and away the highest per-capita alcohol consumption in Europe. Today, the Gallic exception has disappeared. Nonetheless, France remains among the top three or four consumers on the continent and 11th in the world. Alcohol accounts for more than 45000 deaths a year, and the country's premature death rate among males due to alcohol is 30% above the European average. Moreover, new patterns of drinking suggest a growing interest in inebriation, especially among the young. The argument that the Loi Evin has made much of a difference is, at best, unproven.

. Schofield is a journalist based in Paris.