“…In the economic aspect of sustainability for free zones, there are a set of proposed indicators as follows: the capital investment indicator [12,13,31,[39][40][41], foreign direct investment indicator [4,13,29,31,39,40], revenue increase indicator [4,13,29,33,35,40,42,43], capacity indicator [12,29,31,33,41,44], efficiency indicator [5,12,13,35,39,[43][44][45][46], quality indicator [4,5,29,33,35,[39][40][41][42]45,47], tax incentives indicator [29,48], and supportive infrastructure indicator [4,…”