This part summarizes some of the key characteristics of quotas as regulations and as products of negotiations. Insights for managing new and ongoing problems may be gained by studying aspects of quotas in the historical record. A first step is to review quotas as used in practice. As with other negotiated outcomes, international environmental quota agreements set out guidelines for behaviour designed to accommodate partially conflicting interests. In terms of the three criteria valued in regulations - effectiveness, efficiency and fairness - each party desires regulations that show some promise to effectively avoid the 'worst' situations, using efficient means, and in a way that it finds 'fair'. Indeed, unless some balance is found for all parties, an agreement will probably not be forthcoming or will not be very durable. This balance 'solves' the scientific/ ecological, political/ economic and coordination/ assurance negotiating subproblems.