Abatements Close Appraisal Gaps

In legacy cities, new construction often fails because sale prices won’t cover build costs—the 'appraisal gap.' Philadelphia’s 10‑year abatement that taxed land but not new improvements raised attainable values enough for small builders to fill vacant rowhouse lots, adding ~60,000 units with little displacement. A cross‑river comparison shows Camden’s megaproject subsidies underperformed this simple, bottom‑up tool. — It suggests cities can revive housing and neighborhoods by tweaking tax design to favor improvements, not by chasing headline megaprojects.