The Cannes Lions festival of creativity is not just the benchmark of excellence in advertising: it takes the temperature of the industry and culture more broadly. To win at Cannes, work has to “win” hearts and minds in the real world. So the fact that women were higher up the agenda than ever before in 2015 is a big deal.

The festival welcomed more women judges than previously, including me – nearly one-third of the overall panels and five jury presidents were female – and delivered a considered, forward-thinking content programme. We saw the launch (and wide media pick-up) of the Glass Lion – the Lion for Change – celebrating progressive work in the field of gender representation, with Proctor & Gamble’s Touch the Pickle a taboo-smashing inaugural Grand Prix winner. All this, along with better-known work such as Always’ #LikeAGirl, shows an industry waking up to its responsibility as interpreter and shaper of culture.

Evidence shows that traditional stereotyping within advertising and film holds women back. The Geena Davis Institute on Gender in Media provides a bank of research on gender inbalance both in front and behind the camera. Beyond nurturing gender parity within our own agencies, we have an industry-wide responsibility to convey people fairly.

My hope now is that we run with the momentum of the first “feminist” Cannes to encourage greater gender parity in our industry – and this begins at home. But while the moral case for business leaders to check their own diversity creds is evident, the business case for workplace equality still needs stating.

A hefty body of research (pdf) across markets supports the economic advantages of gender-balanced workplaces. Companies with full access to the best talent (regardless of their chromosomal make-up) improve retention, remain competitive and prosper.

Yet the World Economic Forum in its Global Gender Gap report 2014 estimates that it will take until 2095 to achieve global gender parity in the workplace. That’s 80 more years to wait until business and economies are led equally. If you haven’t yet viewed Ernst and Young’s starkly brilliant countdown to gender parity urging business to “fast forward”, I highly recommend it.

Looking specifically at our own industry, it is broadly claimed that the pay gap in media stands at 20-25%. And despite starting to see some positive growth, the glass ceiling persists. Lindsey Clay, vice president of WACL (Women in Advertising and Communications London), recorded how this stacks up and while we start out in the industry at a 50/50 split, only 25% of women hold the most senior roles.

For me, this is as much an issue of women having access to the same benefits, privileges and respect their male colleagues enjoy as equality of pay, which is obviously crucial too. Business leaders can help to shift entrenched leadership norms by instilling a succession pipeline of female leaders and unconscious bias training. It won’t happen overnight, but senior women can become catalysts by helping others climb the rungs with supportive mentoring and by forging strong networks.

Advertising needs to create accessible ideas that represent everybody and to find effective, accessible ways of presenting them. Unfortunately, we will continue to find the same solutions to this challenge unless we have more diverse minds approaching it.

So, we need to encourage and promote more female creative and planning talent and while we’re at it consider a progressive approach from all different points of view: age, economic background, education, sexuality – the works.

Creating the conditions that attract and nurture diversity is a particular challenge for agencies (and most corporations). They tend to be headquartered in capital cities, where the cost of living is very high. But there are initiatives that can help. Introducing internships that lead to first jobs for 18- to 21-year-olds who have not attended university is one idea to challenge the cycle of economic advantage. And while we’re at it, can we please scrap the catch-all millennial tag that brackets everyone aged 18-34 years old into one lump? How unconducive to diversity is that?

Equally, we need to be more conscious of age bias at the other end of the spectrum. How well are the over-50s represented? How are we helping to retrain them in digital skills while valuing their experience?

Advertising, arguably more than any sector, has a moral duty to represent society at large in its output, and in turn remain credible and profitable. We can start in the most tangible, personal way possible by examining our own figures. Only when we are fully transparent will we begin to create truly diverse agencies.

Lindsay Pattison is the worldwide chief executive of Maxus and president of WACL.

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