Each year,
Forbes employs a team of more than 50 reporters from a variety of countries to track the activity of the world's wealthiest individuals. Preliminary surveys are sent to those who may qualify for the list. According to
Forbes, they received three types of responses – some people try to inflate their wealth, others cooperate but leave out details, and some refuse to answer any questions. Business deals are then scrutinized and estimates of valuable assets – land, homes, vehicles, artwork, etc. – are made. Interviews are conducted to vet the figures and improve the estimate of an individual's holdings. Finally, positions in a publicly traded stock are priced to market on a date roughly a month before publication. Privately held companies are priced by the prevailing
price-to-sales or
price-to-earnings ratios. Known debt is subtracted from assets to get a final estimate of an individual's estimated worth in United States dollars. Since stock prices fluctuate rapidly, an individual's true wealth and ranking at the time of publication may vary from their situation when the list was compiled. Family fortunes dispersed over a large number of relatives are included only if those individuals' holdings are worth more than a billion dollars. However, when a living individual has dispersed his or her wealth to immediate family members, it is included under a single listing provided that individual is still living. ==Annual rankings==