A joint bank account has, traditionally, been a sign of commitment. As newlyweds start their lives together, it is perhaps the clearest way for them to say, to each other and to the world, “What’s mine is yours, and what’s yours is mine.”

But these days, some young couples are skeptical. “There has been a generational change,” said Joanna Pepin, a doctoral candidate at the University of Maryland who studies the organization of money in romantic relationships. “The research we have shows that, cross-culturally, more people are keeping money separate.” Indeed, a Bank of America study published earlier this year seemed to suggest that Millennial married and cohabiting couples were more likely to hold separate accounts than previous generations were.