The world's richest individuals increased their wealth by a weighty $1 trillion, or about 750bn, in 2017. Most of us here in the UK battled stagnant wages [and] rising shop prices. In fact, the figures are quite startling. Bloomberg's Billionaire Index, which measures the wealth of the world's top 500 people, shows that the richest of the rich controlled a total of $5.3 trillion in 2017, up from an already staggering $4.4 trillion at the same point in 2016. For context, the United States of America - the world's largest economy - has a gross domestic product of somewhere around $19 trillion. So all in all, not a bad year to be a billionaire. But what does it mean for the rest of us? Back in 2016 ... a group of academics from such esteemed institutions as the University of Oxford, London School of Economics and Cornell University found that as the rich get richer the rest of us get grumpier. The findings were quite clear: in societies where the richest control the majority of the country's income, the population as a whole is more likely to report feeling "stressed", "worried" or "angry". As the rich get richer, they are responsible for pricing certain goods and services out of the reach of the rest of the population - think top schools, the best hospitals and property in particularly desirable locations. And then there's also a crucial psychological factor that may play a part: seeing the most prosperous becoming even more affluent might make you feel like your chances of moving up the ladder are fluttering away.