It is well recognized in the development literature that movement in and out of poverty is caused by several demographic, economic and natural factors that are within and outside the control of the household. This chapter uses primary data collected from a sample survey to understand the major factors behind changes in economic conditions in a coastal province in South Vietnam. The survey was conducted in 2001 in five purposively selected villages to: (i) understand the livelihood systems in the Vietnam coastal area; and (ii) analyse the impact of government intervention (construction of embankments and sluices to prevent saltwater intrusion) for water management on rural livelihoods. A comparative analysis of costs and returns of intensified rice farming, rice–shrimp farming and semi-intensive shrimp farming is conducted to study the effect of the change from the brackish-water to the freshwater system on the productivity of land, the most important asset possessed by rural households. An income determination function is estimated to analyse the effect of the endowment of various capital items on household income. Farmers were asked to report changes in economic conditions over the last 10 years and the reasons behind the changes. These qualitative data were related to the endowment of capital at the household level to analyse the factors contributing to the poverty dynamics in the region.