Seventy-two different metrics were assessed and divided into these categories: economy (GDP per capita, employment levels, wage rate); research and development (number of patents, startups and presence of top universities); cultural interaction (proximity to World Heritage Sites and number of theatres, museums, stadiums and hotel rooms); livability (life expectancy and rent prices); environment (air quality and waste recycle rate); and accessibility (the price of a cab and the number of international flights).