Baby boomers account for the biggest share of homebuyers in the U.S. today. Most are downsizing in their golden years — selling a bigger house and purchasing something smaller. But an increasing number of a baby boomer households are reversing that pattern —they’re upsizing.To learn more about this trend, “Marketplace Morning Report'“ host Nova Safo spoke with Rachel Ensign, an economics reporter with the Wall Street Journal who’s covering the change. The following is an edited transcript of their conversation.Nova Safo: So, the typical pattern is your kids grow up and move out, you retire, you downsize. Maybe you cash in some equity. But you found that a lot of baby boomers are doing something different. Can you walk us through that?Rachel Ensign: What these baby boomers — who are pretty well off in general — are doing is they're actually upsizing. They're buying bigger homes, or they're doing big renovations to their current homes to improve them and make them bigger.Safo: And why are they doing this?Ensign: The number one factor behind this, I think, is just that baby boomers have so much money. Especially compared to to prior generations, boomers have more wealth than any other generation currently alive. So before, it made a lot of sense to downsize if you really needed that money from selling your bigger home. But now, if you don't need that money and you in fact just have lots of extra money, why not build a bigger home?Safo: What is the rationale that you were hearing from seniors when you covered the story about why they want to either build a bigger home or add to their homes — maybe make it nicer, new kitchens. What are they telling you about the kind of lifestyle rationale of why they're doing this?Ensign: A lot of it has to do with their families. They generally have grown kids, and a lot of them have grandkids, and they want to be able to host their extended families, even if it's just a few times a year for Thanksgiving or Christmas. They want to have space so that their kids and grandkids want to come visit and stay a while — that is is a really big motivator in in buying these bigger homes.Safo: If seniors aren't selling their homes — or they're buying bigger ones instead of downsizing — how does that reshape the real estate market?Ensign: The way I think about this is: It's a part of this broader housing market situation where — like you said at the beginning — boomers are the dominant force. Still, they make up the largest share of homebuyers in the U.S. And then on top of that, a lot of boomers are just staying put in these three-bedroom-plus homes. They don't want to sell, they don't want to move, don't want to downsize — so they're just staying. And that is is definitely a factor in why there's such low inventory in a lot of places, and it's changing the nature of a lot of these communities. These are communities in the suburbs, in a lot of instances, that used to be full of families, and now it's actually a lot of older people who are staying in their homes.