According to the article, is mostly speculators betting that the property values will rise faster than the market consensus (these speculators don't want to be locked into leases that will soon undervalue the property). Also, it is arbitrageurs who think they can profit by repurposing the units (e.g., hotel/airbnb conversion).

When laws are very tenant-friendly (impossible to evict, caps on deposits etc), having tenants becomes a liability, which depresses the value of the building, especially if you only want to hold on to it for a few years.

Because renting doesn't make you that much money and you have to work for it. Just leaving it sitting there and selling it later is no effort profit

If the value rises considerably in a few years for you to make a decent profit, then its mostly a headache (and operating costs, wear and tear etc) to have tenants .

"You gotta spend money to make money."

I write that in a somewhat tongue-in-cheek way usually, but getting and caring for a tenant could, in some cases, be more expensive than leaving the space vacant. If you own the property outright, it's a measure of the cost of extra wear-and-tear, property tax, any other fees and fines, and maintenance (like this new one) against the rent you collect.

It's not always the case that the rent is going to be a bigger number than tax, fines/fees, and extra wear-and-tear, especially if you own the property outright. If you add in rent control and a rising trend in rental prices, some landlords would rather leave the space vacant for a while to wait out the market for higher prices.

You could easily lose money if you don't recognize and account for all of the costs.

My guess is that these are unsanitary, and renovation is too expensive. So they let the building sit there until they find a buyer, speculating for an increase in value. Possibly a buyer who intends to demolish the building in order to build something else.

I suspect some of it is tax liability. (I am not an accountant) but I think you can deduct the “loss” of rental income you didn’t get against other properties you may own. If the ammount of the loss is “rent you could have gotten but didn’t” instead of “market rate”, you’ll just keep the rent high.

I’m in Cambridge MA and the Harvard square movie theater sits empty 5+ years and i can’t think why excepting financial shenanigans. (Though apparently there is finally a plan to redo the building)

You know how some people say that if you're going for investors for your start up, it's better to sell them on user engagement & growth rather than revenue, because revenue brackets what you're potentially worth? I bet it's something like that. If you rent at a certain price, that brackets the property (and depending on the lease, maybe even locks it in).

The value of the property is based on its rentable value so if the landlord drops the rent to get a tenant in they immediately take a big loss on the value.