) , also known as Tong Yang Xi
) in Chinese, was a tradition of arranged marriage
, in which a poor family (burdened by too many children) would sell a young daughter to a richer family for labour, and in exchange, the poorer family would be married into the richer family, through the daughter. The girl acted both as an adopted daughter (to be married with a young male member of the adopted family in the future) and free labour. Due to the lower-class status of the girls, discrimination was often present, and slavery-like treatment was not uncommon.
These marriages were rarely successful, principally because of a lack of sexual attraction between the husband and wife. This has been explained as a classic demonstration of the Westermarck effect.
Shim-pua marriage fell out of practice in the 1970s due to increased wealth from Taiwan's economic success making these arrangements unnecessary. A direct translation of "Shim-pua" is simply "little daughter-in-law", and "Tong Yang Xi" means "child daughter-in-law."
) is a related custom by which a wealthy family that lacks an heir might take in a boy child. The boy would take on the last name of his new family, and typically would marry the family's daughter.