Valentine’s Day is fast approaching (this weekend, in case you forgot), and Americans are being exhorted to celebrate romantic love — to the tune of $19 billion. Even on non-holiday weekends, the celebration of marriage, dating and sexual partnership is big business. The online dating industry in the United States is worth $2.2 billion and is expected to grow by $100 million per year through 2019.

Almost anyone would agree that romance is wonderful, but it’s not necessarily a part of every life. What about those who are single?

Today’s veneration of true love, soul mates and intense companionship is a relatively recent cultural development. Its rise in importance means that the way our society views those who live unpartnered has changed. Marriage has always been the norm in the United States, but unpartnered roles like maiden aunt or confirmed bachelor — which used to be relatively dignified, if not celebrated — have come to be viewed as either pathetically lacking, masking unacknowledged romantic desires or just weird.

The view of romantic love as a pinnacle of human existence isn’t solely a pop-culture creation. It has now been affirmed by the government as well. Over the summer, in the Obergefell v. Hodges decision on gay marriage, the Supreme Court enshrined marriage as the most (and some might say only) valuable state in life. Justice Anthony Kennedy opined that “no union is more profound than marriage” and that it is “essential to our most profound hopes and aspirations,” and implied that those who remained unmarried were “condemned to live in loneliness.” Though the ruling on gay marriage itself was joyous for many, some of those lines left a bitter taste in others’ mouths.

Yet today, unpartnered people are playing an increasingly larger role in American life, and demographic trends imply that this won’t change. In 2014, for the first time since the Bureau of Labor Statistics started tracking the numbers, there were more single adults than married ones, and the share of never-married Americans is at an all-time high. Time magazine recently hypothesized that 25 percent of the current generation of millennials will never get married, and polls show that young people are increasingly likely to see marriage as obsolete. Writers and commentators are beginning to reclaim old models of singlehood, and the media’s fascination with life paths other than marriage — religious celibacy, for instance — seems to be gaining popularity.

Do we know what’s causing the shift away from marriage and what society might look like in the future? How has our conception of singlehood changed over time, and are there serious movements to change how that state is viewed? What does the research show us when it comes to which form of life is truly better?

Over the next few days, we’ll hear from:

Bella DePaulo, project scientist at the University of California, Santa Barbara

Sarah Wright, board chair of Unmarried Equality

Stephanie Coontz, professor of history and family studies at the Evergreen State College,

Eve Tushnet, Catholic author and blogger,

Michael Cobb, professor at the University of Toronto,

Naomi Schaefer Riley, fellow at the Independent Women’s Forum,

Lisa Bonos, writer and editor for The Post’s Solo-ish blog,

W. Bradford Wilcox, director of the National Marriage Project at the University of Virginia.