The oldest of Gen Z is influencing the economy in a big way. Tim P. Whitby/Getty Images The oldest millennial and oldest Gen Zer are in charge right now - of spending, influence, and the economy. The 40-year-old's financial behavior is shaping huge economic markets like housing. Meanwhile, the 24-year-old is setting trends, affecting consumer behavior for everyone. See more stories on Insider's business page. The 40-year-old and the 24-year-old are the talk of the town right now.