I feel like we have shifted from an intergenerational 'positive sum' mindset to a 'zero-sum' mindset. The pie is not getting bigger anymore – now the question is: Do I claim my piece of the pie, or do I leave some for other generations? Two fundamental trends have caused this shift in perception: Demographic change and climate change.

After two devastating world wars, Europe and large parts of the world made an incredible comeback in the second half of the 20th century: Economies grew, innovations improved the quality of life, globalisation and free trade turned luxury items into affordable commodities. The promise of intergenerational social upward mobility was credible: "I want my children to have it better than me" was a sensible ideal to work towards.

But since the 90s, it seems, the pie has slowly stopped getting bigger – at least in Europe. I don't have the impression that Millennials and Gen Z are very optimistic about the future. Our societies are getting older, which will eventually cause our social welfare systems to collapse. At the same time, we are heading towards an ever-warmer climate, which will have severe impacts on our future prosperity and safety.

Why should we pay into health and pension systems that we don't believe we will ever profit from ourselves? How willing are we to curb our own consumption and compromise on our quality of life to combat climate change?

We have lost intergenerational solidarity because we lack credible positive visions.