Based on the theory of Welfare Economics and market structure theory this paper analysis the concept of carbon tax and externality of the consumers and producers in the forests carbon sink market, belive that the impact of the market is correcting externality, prove that the forests carbon sink market is oligopsony at presant.

A Legal Perspective Study on Buyers Remedy in Case of Sellers Breach of Contract in International Goods Exchange;

The paper explains some precautionary economic ways of guaranteeing all the rights of buyers, starting from the call for trender, during contract signing, in case of payment of loans up to securing all buyer s privileges during the period of defect liability.

This paper mainly analyzes the causes and various styles of the fraud of L/C,and illustrates the corresponding preventive measures which the buyers,sellers and banks should take.

Formation of buyer's market is changing old commodity structures,even economic structure.

Based on buyers principle, an inherent consistency was proved in the solutions.