To eradicate poverty, one needs to understand the dynamics of poverty as well as vulnerability to
poverty. Specifically, people move between poor and non-poor states. Under a specific policy
intervention, the poor could be able to exit the poor state. But, another policy intervention could
make the non-poor who are vulnerable to poverty to enter the poor state. We use the household
Socio-Economic Survey (SES) to assess household vulnerability to poverty in Thailand between
2002 and 2004 and uses qualitative method to assess social protection institution for vulnerability.
From the SES, approximately 19.1 percent of the rural households were transient poor and 9.4
percent are chronic poor. Using the same methodology and definition of vulnerability to poverty
as Bidani and Richter (2001) and Chaudhuri et al. (2002), we find that approximately 44.0 and
51.8 percent of rural households were vulnerability to poverty in 2002 or 2004. Approximately
35.0 percent were vulnerability to poverty in both years. These households were more likely to be
male-headed households, or own-account or economically inactive households, live in the north or
northeast regions or be headed by lower than upper elementary educated persons. Using a
qualitative method, we find that middle income classes among the Thai view vulnerability concept
in a broader view than the vulnerability to poverty. Risks they exposed are predictable and
manageable. But, the main problems are they do not know how to manage or cannot get access to
existing institutions or cannot get involve in public policy decision to protect them from
predictable risks. Under the social protection mechanisms provided by the current formal
institutions, we find that such institutions had used a high level of discretion when allocating cash
and in-kind benefits and repeat receipts of cash and in-kind benefits was not uncommon.