The home-equity market has been down so long it doesn’t take much to make it look like it’s looking up. Firming house prices in 2013 may be leading to a revival. The outstanding balance of home-equity loans, including home-equity lines of credit and closed-end second mortgages, continued to decline during the second quarter, dropping another 2.3 percent, according to the Federal Reserve. Since the end of 2007, the home-equity market has shrunk by 35.5 percent. Depository institutions hold...[Includes three data charts]