Waves of mass migrations from Hong Kong villagers exercised their right of abode in the United Kingdom and left for Europe. In 1967, a series of large-scale riots erupted in Hong Kong, causing social instability. These events led some of the richer Hong Kong residents to move abroad. Emigration took place to countries in Southeast Asia, South Africa or South American countries. This wave did not come to a rest until the mid-1970s. On the 19th of December 1984, the People's Republic of China and the United Kingdom signed the "Sino-British Joint Declaration", validated the 1997 transfer of sovereignty over Hong Kong to China. The declaration prompted
British Hong Kong franchise to include them. The Sino-British Joint Declaration was signed by both the Prime Minister of the United Kingdom and the Premier of the People's Republic of China on 19 December 1984 in Beijing. The Declaration entered into force with the exchange of instruments of ratification on 27 May 1985 and was registered by the People's Republic of China and United Kingdom governments at the United Nations on 12 June 1985. In the Joint Declaration, the People's Republic of China Government stated that it had decided to resume the exercise of sovereignty over Hong Kong (including Hong Kong Island, Kowloon,