The state’s chronic failure to accurately value Baltimore’s vacant land is likely unique to the city, according to a follow-up report from a research and policy think tank.

And there’s good news — this year’s assessment data shows Maryland has made progress addressing the errors.

In August, the Center for Land Economics found the city had potentially missed out on millions of dollars in revenue due to how the state calculated tax values for vacant properties. The nonprofit group, which advocates for taxing land instead of the combined value of land and improvements, wanted to determine if the problem was statewide or specific to Baltimore.

Its latest paper, out Thursday, concludes it’s likely a localized issue and that Baltimore is a “dramatic outlier” in Maryland. Vacant land in Baltimore often sells for two to five times its assessed value, the study found. Researchers said the valuations were “not based on market evidence,” suffered from “data quality gaps” and had “administrative challenges unique to Baltimore City.”

“Our findings show that Baltimore’s situation is not inevitable or embedded in state law,” study co-author Lars Doucet said. “It’s a localized problem with localized causes.”

But those disparities mean Baltimore’s homeowners, businesses and renters — paying the highest property tax rate in the state — share a disproportionate tax burden relative to vacant landowners. Baltimore estimates having more than 20,000 vacant lots, a phenomenon that officials have been slow to curb due to the volume and expense associated with redeveloping them.

Proponents of a land value tax argue the city’s tax structure enables speculative investors to sit on vacant parcels without being incentivized to build on them. Others have alleged the relatively high tax burden pushes investors and homeowners away from Baltimore.

But that might not be the case much longer. The center, after reviewing the latest round of assessments data, found vacant land in Baltimore to be valued “more consistent and market-aligned than in prior cycles.”

The head of the Maryland agency responsible for determining property tax values publicly acknowledged the problems last year and pledged to overhaul the agency’s methods after the August study’s publication.

Bob Yeager, director of the assessments office, said in a Thursday statement that the agency has been working collaboratively with Baltimore’s property transfer office as well as with internal databases, current land assessments and sales records to overhaul its processes.

So far, Yeager said these efforts have led to a “net increase” in land values, though the department has also observed many tax-exempt lots.

“This proactive strategy ensures vacant land valuations are properly reflected,” Yeager said.

Greg Miller, the report’s co-author, has said the think tank wanted to focus on Baltimore after hearing compelling anecdotes from community members about land value discrepancies.

The group’s first report confirmed those murmurings. It found that SDAT would base a land’s worth on what was built on it. That means two pieces of land in the same neighborhood, with the same zoning characteristics and of similar size, could have different taxable values if one was built out and the other wasn’t.

Changing how land parcels are assessed, and taxed, is one of several big ideas being floated as Baltimore seeks to reduce its supply of vacant homes and empty land over 15 years. The idea gained traction in Detroit when longtime Mayor Mike Duggan lobbied for the change in 2023. It has failed to pass the Michigan Legislature, with opponents arguing the unpredictable economic effects will cause foreclosure rates to increase.

Maryland state legislators are considering the measure in this year’s General Assembly session. In a January hearing, bill sponsor Del. Vaughn Stewart said the bill should be considered a nonpartisan approach to building more housing and development during tough economic periods.

“Right now our property tax system quietly punishes people who build things,” Stewart said, “and it rewards people who sit on things.”

Critics of the measure said it’s almost guaranteed to raise taxes, especially on large landowners, and could lead to a flurry of constituent appeals. They also said it could cause even more skepticism for housing developers wary of Maryland’s cumbersome regulations adding costs to projects.

A separate proposal, which authorizes Baltimore and other jurisdictions to impose higher tax rates on vacant and abandoned homes, is scheduled to take effect in the city this year. A bill introduced in August would amend the provision to include Baltimore’s vacant lots. It’s scheduled for a hearing in May.