Multi-story buildings are very uncommon on South Tarawa. The high population is accommodated through large household sizes, with an average of 7.3 people per household, on small land plots. Most land is owned by the original families or ''kain Tarawa'', although in the main centres of Betio, Bairiki and Bikenibeu there are large areas of land on long-term lease to the government. Without access to family lands or government housing, many South Tarawa residents have no choice but to become squatters; disputes over land are common.