“…The literature is dominated by point source emission or ambient permit trading systems (Neil, David, Moore, & Joeres, 1983;Eheart, Brill, Lence, Kilgore, & Uber, 1987;Leston, 1992;Weber, 2000;Hung & Shaw, 2005). We discuss three types of non-point source discharge permits trading system proposed to date: an ambient permit system, a trading ratio system and a zonal permit system.…”