SEOUL (Reuters) - As South Korea scrambles to halt the sharp decline in its birth rate, policymakers are having a hard time convincing many in their 20s and 30s that parenthood is a better investment than stylish clothes or fancy restaurants. Asia's fourth-largest economy plans to launch a new government ministry dedicated to demographic challenges after years of incentives failed to ease the baby crisis. But for Park Yeon, a 28-year-old fashion Instagrammer and aspiring singer, spending choices are guided mostly by her appetites for clothing and travel, leaving little budget for marriage and babies.

"I'm all about YOLO (you only live once)," said Park as she sells her Supreme T-shirts at a thrift fashion festival in Seoul's high-fashion enclave of Seongsu-dong. "There isn't enough left to save each month after I do things to reward myself. Getting married might happen at some point but being happy right now - that's more important, right?" South Korea continues to break its own record for having the world's lowest birth rate, which hit a fresh low last year.

Sociologists say the lifestyle priorities of Koreans in their 20s and 30s - considered Generations Y and Z - mean they spend more and save less on average than the wider population or their peers in other countries, neither of which are conducive to nest building. "They are status hunting. Their high spending habits show young people are working on their own emblems of success online rather than focusing on the impossibl.