The poor performance of many government or public irrigation systems is well documented. This study uses a model including internal and external assurance, commitment, and fairness to explain the performance of irrigation in the Philippines, Sri Lanka, Nepal, and Maharashtra State in India. The suggested approach is superior to ones based on the concept of ''free rider'' or government failure. The analysis shows that the Philippines and Maharashtra have developed ways to improve assurance concerning the actions of government and other irrigators which has improved irrigation performance. In contrast, Sri Lanka and Nepal have provided little assurance in their government irrigation systems and performance is poor. ¿ American Geophysical Union 1993