What percentage of people in the world are gay?

The US Census does not collect data on sexuality; however, according to a recent study by the Williams Institute at the University of California, 11% of the adult population has engaged in same-sex sexual behavior, but only 3.5% of the population identifies as being lesbian, gay, or bi-sexual.

As homosexuals are still persecuted in the United States, it is likely that most of the 11% who engaged in same-sex sexual behavior are gay or bisexual but have chosen to not identify as homosexual in order to conform to cultural pressure.