This paper shows that the recent increase of single-person households in thelast decade has resulted from delayed marriage among the young populationand stronger tendency for old people to live separately from their children.Factors such as working status and pension incomes have differing impacts onthe decision to form a single-person household between men and women.Delayed marriage is more pronounced among working women, and publicpensions have contributed in the increase of single-person households amongold women. One potential policy implication is that the factors distorting thechoice between work and family needs be removed to prevent inefficientlydelayed marriages among the young population.