Over the last few weeks, a number of people have told me that, when it comes to their current home, they have a number in mind. They more or less said, "I've already spoken with my husband/wife about it and, if someone were to offer us $X, we would sell and move immediately."

What's fascinating about this is that it's a form of housing supply that generally doesn't exist anywhere right now. Sure, the people I was speaking with would sell and move for a price, but how does something like this actually happen? How do buyers find them?

I suppose it could happen through word of mouth. I now know their prices and so if someone I know were interested in such homes, I could tell them. It is a low probability, but it's still a possibility. Alternatively, someone (an agent or otherwise) might just show up on their doorstep and make them an offer. My dad actually sold his last home this way.

But again, how likely is this to happen? It doesn't seem scalable. And this is why Zillow used to have something called a "Make Me Move" listing. Rather than a traditional listing, it was a listing for, "I don't necessarily need to sell, but if you offered me $X, I would move." For whatever reason, though, Zillow no longer offers this service. Presumably, it's because it wasn't working. Hmm.

Here's how I'm thinking about it.

Today, most housing markets are binary. A home is either for sale or it's not. Sometimes enterprising people manage to secure an "off-market home", but generally speaking the market is binary. If a home isn't for sale, most people don't usually bother with it. Mostly because they can't easily find it.

But market conventions aside, the conversations I've been having suggest that it's actually more of a gradient. On the one side are people who really don't want to sell. Maybe they're never sellers. Let's pretend that the home has been in their family for generations and so to convince them to sell you'd probably have to offer them an absurdly high price and that might not even do it.

On the other end of this gradient are people who are ready to sell today. In an extreme example, they might even need to sell by a certain date, or else. In this case, a below-market price could get them to sell. They are highly motivated and one sure-fire way to increase speed is to lower price.

But for everyone else in between, it is a big unknown gray area where price and desire to sell are, I would think, inversely correlated. As desire to sell increases, expectations around price probably need to come down until they reach a point where the market can bear it and a transaction will occur. This is my hypothesis at least.

But if it's true, and there's a big untapped gray area, then the housing market is a lot bigger than we think it is.