In a normal market, an empty home is a wasting asset: Equity sits trapped, no rent comes in, and the owner keeps paying property taxes, insurance, maintenance, utilities, and fees. But the math has started to bend the other way in some markets, according to a new analysis. The study  from Flock Homes , a real estate investment platform, found that in 49 metros, the modeled cost of keeping a vacant home for at least five years was lower than the estimated tax hit from selling. In Los Angeles, it would take nearly 19 years of holding costs before vacancy became more expensive than selling. It’s a shocking finding because the logic runs counter to everything a housing shortage should reward: Even as home prices sit near historic highs and buyers are desperate for more listings, some owners may find that selling triggers a tax hit so large that holding on to an empty home makes more financial sense—keeping properties out of circulation when the market needs them most.…