What does a woman need to succeed? The Times celebrates International Women's Day on Friday with its own list of female achievers. Mary Ann Sieghart explains the form

Women's lives have changed immeasurably. But how much power do they have to change other people's lives? We have come a long way, we are told, but if the destination is the summit upon which men have always been perched, only a few women have joined them. And we are still a far cry from capturing it.

Over the next four weeks, The Times will be running a list of the 100 most powerful women in the world. With the help of our foreign correspondents, six Times women journalists compiled a shortlist, which we then ranked in order. To help us to place the candidates, we gave marks according to three criteria - political power, financial power and personal influence.

It was surprisingly - and disappointingly - hard to come up with eve 100 women who could truly be judged powerful on a worldwide scale. Of the 292 nation states, only six have female prime ministers and two have women as heads of state and government. Some parts of the world - notably Africa, the Middle East, Russia, Australia and Latin America - were lamentably lacking in powerful women. The list is dominated by Europe, North America and Asia (which has more women prime ministers than any other region).

To say that Britain contributes 14 to the list, second only to America, and that Sweden has none, is not necessarily a sign that this country is more advanced in its treatment of women. For the power of the women on this list is at least partly determined by the power of their nation: inevitably the Governor of Finland's central bank, for instance, will come lower down the list than a member of the Clinton Cabinet. But it is still interesting that, in the Scandinavian countries which have done so much for ordinary women, there are so few at the very top.

About a quarter of these women were given a helping hand by their fathers or husbands. In Asia in particular, politics tends to be dynastic many of the prominent women there are widows or daughters of assassinated politicians. Hillary Clinton, of course, enters the list by virtue of the active part she plays in her husband's career; other women have inherited huge businesses and gone on to run them. But to qualify for inclusion, all have had to have made something of their inheritance and to be welding power on their own account. Simply to be rich orfamous was not enough: neither Joan Collins nor the Queen Mother, for instance, made it over the threshold.

The list is dominated by politicians and administrators; female thinkers are particularly sparse. We could find just two women scientists in the world who deserved a place, and no queens of new technology. Neither an historian nor a philosopher sprung to mind, although three feminists made it into the top 100 by virtue of the global reach of their message.

Even the financial world, despite the rise of women through its ranks, can boast very few at the summit. Of the nine businesswomen who make it into the top 100, four inherited their companies from husbands or fathers. Only three started them from scratch, and two are paid employees.

So are women being held back, or should they blame themselves for their relative lack of power? In politics, women generally have to be twice as good as men in most nations to be taken seriously. Even in liberal, prosperous countries such as Britain, there is much covert discrimination that mitigates against women reaching the top. In many more traditional countries, it is still unthinkable.

International organisations such as the UN have a few women in very senior jobs, but they still represent a paltry percentage. The private sector does little better: big businesses seem reluctant to promote women to the level of chief executive or chairman. Glass ceilings have yet to be shattered in most walks of life. Yet in the two areas where women could be mistresses of their own destiny - entrepreneurial and intellectual activity - they are still woefully under-represented.

DO women perhaps lack the drive to compete with men at the highest echelons of life? Do they become distracted by family responsibilities, or are they simply not prepared to sacrifice a rounded life for the narrow, channelled existence that serious success demands? It is worth asking these questions, however, uncomfortable they make us feel. Discrimination certainly exists and life at the top is unforgiving for mothers. But it would be wrong to put the entire blame on men or on the system for our inadequate representation in the corridors of world power. We have to look into our own hearts too.

58) Emma Bonino, Italy, 48

It is not surprising that Emma Boning has a reputation for gutsy, forthright assertion of European consumer rights, fishing interests and humanitarian aid, which is her portfolio at the EU Commission in Brussels. As an MEP, deputy speaker of the Italian Parliament and Secretary General of the Italian Radical Party before her elevation to Brussels, she has been a determined critic of authority in all its forms. She used to campaign against backstreet abortions, nuclear energy and the death penalty with an energy and appetite for publicity stunts which earned her the nickname "The Cyclone". She now uses her resourcesto help Kurds, Bosnians and Afghans, and defend the rights of EU citizens on consumer issues form shopping hours to train timetables.