When we started out, we didn't really think that the era of great opportunity would end one day. We were much too busy developing our companies. But in today's China you can build a city, even a mega-city like Beijing or Shanghai, within 10 or 15 years. And then you are done. So in real estate development, the Gründerzeit is over. But that is not the case in other sectors.

Many years ago, we were only able to build boxes. Today, architects from all over the world are working with us - Zaha Hadid from London, Gerkan, Marg and Partner from Hamburg, Kengo Kuma from Japan. We brought design and digitalization from abroad to China.

It's a good thing that it is getting simpler to register a company in China, it is good that the exchange rate of our currency is getting more flexible and that it's getting easier for Chinese businesspeople to travel. All of this opens up our economy.

I'm afraid what we are building today will not have the same impact and sustainability of the architecture of a 100, 500 or 1,000 years ago. The buildings of those days were miracles. We don't perform such miracles today. So we should be a little more modest. For my part, I'll be glad to show one of my buildings one day to my grandchildren and say: I'm proud of that.

Because people along the route had realized that there was demand and quickly organized supply. That's so Chinese. In a well-organized country like Germany, such a problem may not have arisen in the first place, but in China people immediately recognized an opportunity.

China reformed its state sector before, in the late 1990s. Tens of millions were laid off at the time. That was scary and we had warnings of social unrest. But it did not happen. Instead, there was a restructuring in our economic system. I am not sure if China will follow a Western playbook in this respect.

Growth will be slower, no one denies that. But the question is: Where are the chances and opportunities now? I see some positive and some negative trends.