THE centrepiece of the opening-bell ritual at the London Stock Exchange on February 2nd was a roll call to honour 27 global investors. They were lauded for pledging allegiance to the “30% Club”, a group which campaigns for precisely that proportion of women on corporate boards globally. Membership is a hot ticket, judging by the club’s expansion. Behemoths including BlackRock, J.P. Morgan Asset Management and Standard Life have joined, and are voting against boards that fail to appoint more women.

In much of western Europe, such efforts follow a decade-long push by governments. In 2008 Norway obliged listed companies to reserve at least 40% of their director seats for women on pain of dissolution. In the following five years more than a dozen countries set similar quotas at 30% to 40%. In Belgium, France and Italy, too, firms that fail to comply can be fined, dissolved or banned from paying existing directors. Germany, Spain and the Netherlands prefer soft-law quotas, with no sanctions. Britain opted for guidelines.

Companies have rushed to comply. In some countries the share of women among directors of large companies has increased four- or fivefold since 2007 (see chart). Even in Britain it shot up to 27% in 2017, more than double a decade earlier. Not that the measures were uncontroversial. In Norway the quota prompted some firms to delist rather than comply; the same may have occurred in other markets. France’s markets regulator has highlighted “circumvention strategies” used by some firms, such as decreasing the total number of board members to increase the percentage of females. In every country business leaders protested when the idea was floated. Xavier Fontanet, former chief executive of Essilor, a French eyewear company, quoted Charles de Gaulle as saying “one may not command without having obeyed”—his point being that women often lack the management experience that makes a good board director. Another objection was that the pool of qualified women was so small that the same few women, or “golden skirts”, would be spread thinly between boards. Hiring committees expressed concern about bringing onboard grievously underqualified directors. Ten years on from Norway’s trailblazing move, the worst fears have not been realised. Take the worry about golden skirts. “Over-boarding” is a challenge, admits Richard Hayden of TowerBrook, an investment firm in London. But many male directors are equally stretched. According to ISS Analytics, a research arm of ISS, a proxy-advisory firm, 19% of female directors of Europe’s STOXX 600 companies—which are predominantly in markets with quotas—sit on at least three boards. But so do 15% of male directors. Nor has the threat of professionals being replaced with token women come to pass. Shortly before France passed its quota law, LVMH, a French luxury group, appointed Bernadette Chirac, the wife of a former president, explaining that she attended fashion shows. But four women added to its board since have all been a director or chief executive. A study on Italy’s 33% quota (the law which introduced it will expire over the next few years) found that female directors of the biggest firms were on average more likely than their pre-quota predecessors to have professional degrees and qualifications.

But in other ways the results have been mixed. Many new directors are younger and thus have less or no experience as directors or chief executives, says Lisa Barlow of Egon Zehnder, an executive-search firm, in Paris. In Italy, France and other countries some women have trained for the job at programmes run by board members’ associations. In Germany a shortage of qualified women led to a surge of foreigners onto supervisory boards (there is as yet no quota for management boards). That could be problematic, says Bernhard Stehfest from the Federation of German Industries, because foreigners are less familiar with the firms or German regulations.

While quotas have not been the calamity that many had feared, they have also so far failed to achieve what governments had promised they would. When quotas are put on the table, proponents often produce “snapshot” studies showing that companies with more women on their boards have better returns and are less likely to be beset by fraud or shareholder battles. But causation is hard to prove. Perhaps better-managed companies have more scope to promote diversity. Equally, when studies are conducted before and after quotas are imposed, the results in terms of companies’ performance are inconclusive. Some studies find positive effects; others the opposite or no effect at all.

Neither is there evidence that having more women on boards is changing decision-making. In the experience of Lawton Fitt, a veteran female board member in America and Britain, women do not necessarily express particular views or fill a predictable role in the boardroom. A study in France in 2015 based on interviews with 24 board members concluded that the country’s new quota system led to changes in the process of boards’ decision-making. But there was no change in the substance of decisions, such as whether to approve lay-offs. It also found that the process did not change because the new members were women. It was because they were likely to be outsiders.

Perhaps the most puzzling shortcoming of the quotas is that they have had no discernible beneficial effect on women at lower levels of the corporate hierarchy. The expectation was that they would encourage companies to promote more women in order to fill the upper echelons faster. That, in turn, would help shrink the wage gap between men and women.

But a study in Norway found the quotas had no effect on the representation of women in senior management in the firms where it applied. The gender pay gap shrunk only for the golden skirts themselves. In Norway just 7% of the largest firms have female bosses. In France, a paltry 2% do—compared with (a still miserable) 5% in quota-free America. And in Germany, women make up just 6% of directors on management boards.

Nor are more women climbing the career ladder. In France, Germany and the Netherlands just 10-20% of senior management jobs are held by women, a share that has barely budged in recent years, according to data from Korn Ferry, a consultancy.

Perhaps because quotas have been neither the disaster that many expected, nor the disrupter executives had feared, business leaders have warmed to them. “At least ten more years” of quotas are needed, argues Francesco Starace, boss of Enel, an Italian energy giant. Germany’s minister for women has threatened to require a certain share of women on management boards. The 30% Club is now pushing for that share of women in management roles. Quotas may not have proved their worth. But they appear to be here to stay.