Stumbled across a bit of Luohu trivia that suggests that cross border licentiousness has been promoted on both sides of the border as a means of generating profit. According to the Industrial History of Hong Kong Group,

The opening of the “Shum Chun Casino” in 1931, provided one of the only new areas of passenger growth [for the Kowloon-Canton Railway]. By 1934 passengers visiting the casino were a major portion of the cross border revenue until its closure on 1st September 1936. The impact of the casino’s closure was such that there was a shortfall in the last four months of the year at round 30% of the net operating revenue.