The UBS/PwC report on Billionaires: The changing faces of billionaires reveals the evolving identity of the world's billionaires over the last two decades. Not only has the billionaire population become more diverse in terms of age, sex and nationality through the emergence of new billionaires and intergenerational wealth transfer, but maintaining the "billionaire" status is a significant challenge. Building on our original Billionaire report, which analysed wealth creation, preservation and philanthropy, this report takes a deeper look at today’s billionaire population. Looking back 20 years, we surveyed 1,300 people in the 14 markets that account for 75% of global billionaire wealth and compiled a comprehensive database on the world’s billionaire population.