Growing more Rice with less water: the System of Rice Intensification and water productivity in Vietnam*

We study the effects of a large-scale System of Rice Intensification (SRI) program on the water productivity of rice in Vietnam by exploiting provincial and time variations in SRI uptake and irrigation water supply over the period 2000–2012. Our findings document that the world's second-largest rice exporter could produce 4 million tonnes more rice with the same water supply in the reasonably achievable case of 20 per cent SRI uptake across its provinces. In addition, we find that SRI also increases the output of other crops, due at least partly to its possible water savings and soil nutrition preservation in rice production. Moreover, we show that SRI is more likely to be adopted in provinces with a stronger quality of provincial institutions and a weaker agricultural capital base. Numerous selectivity and randomisation tests affirm that the water productivity effect of SRI is robust to selection in SRI uptake at the province and district levels and addressing potential unobservable and omitted variable problems.