... since it provides main source of income for the households. Therefore, they are accelerating investment, purchasing machines to increase labor productivity and improving product quality. In ... Vinh Phuc, Bac Giang, Bac Ninh and Hai Duong (Digregorio 1999). In these 8 business or to continue maintaining his/her successes in business. For example, individuals or households ... behind this increasing popularity. One is the introduction into the literature, by Caves et al. (1982a), of new input- and output-oriented Malmquist productivity indexes that are defined in...