Demographics data is a reliable metric real estate investors should pay attention to as real estate usually involves an extensive hold period of five to 10 years on average despite other market factors. In particular, examining how demographic cohorts' behavior is changing could help investors build a long-term outlook, said Marcus & Millichap national director of research and advisory services John Chang.

Millennials have been playing a significant role in changing the landscape of real estate for more than a decade. This generation, for example, has pushed the median age of marriage to 29 years old, compared with 25 years old two decades ago.

"That shift, which was led by the 72.5 million Millennials, changed housing demand, urbanization trends and the space demand profile of every type of real estate," said Chang.