Not since the 1940s have this many young adults lived with their parents. New data from the Pew Research Institute looked at people 18-34 and found that more than 36 percent of women and 43 percent of men in that age demographic are living at home. The researchers pointed to several factors they say are contributing to the trend: Among millennials, college attendance is more common; the economy is recovering slowly since the recession of the mid 2000s; and, millennials are increasingly waiting longer to get married and have families of their own.