Interesting! Sept 2018 marks the point where (finally!) more of the world is wealthy than poor. I remember being told to refer to poor underdeveloped nations as the ‘2/3rd’s world’ because it was the majority. That has shifted somewhat. There’s still a long way to go, and this study defines ‘middle class’ globally VERY different to how you and I would in Australia (being $11 per day). But sadly 650 million still live in extreme poverty, struggling to find food each day. Yet this is reducing at the rate of 5 people per second! Also, the environmental impact per person is gradually reducing as technologies change.