Technical efficiency of prawn poly-culture in Tam Giang lagoon, Vietnam

Abstract

This paper measured the mean technical efficiency of 91 percent in prawn poly-culture (prawn (Peneaus monodon)-rabbitfish (Siganus oramin)-others pattern) farms in Tam Giang lagoon, Vietnam, using an input-oriented VRS data envelopment analysis. The estimated technical super-efficiency was then regressed to the farmer characteristics, extension contacts, stocking density, and production environment to identify the determinants of technical efficiency of those farms. Experience of the operators, their attendance to aquaculture training courses were the factors positively influencing farm level efficiency, while prawn stocking density had negative relationship with their technical efficiency. The later results also revealed the problem of congestion in prawn poly-culture production process. Moreover, the positive coefficient of production environment dummy variable indicated the difference between two types of ecosystem: planned farms and unplanned farms. In addition, in comparison between the technical efficiency results of those two groups, the unplanned farms were less efficient than planned ones. A suggestion of planning aquaculture area in Tam Giang – Cau Hai lagoon system and cooperating between unplanned farms and governmental offices, as a result, were made to improve technical efficiency. Moreover, training more extension workers and conducting more aquaculture training courses were also suggested in order to have the desired increase in productivity. Finally is a hint of further study about the congestion problems which have not been dealt in this study.