The policy evaluation that policy-makers expect could be the investigation into causality from input to output as does in tourism research However, can one policy be satisfied with causal inference conditions and a cause of changes in social values? One policy is rarely possible because there are tremendous extraneous variables beyond the policy. Public values also change through unquantifiable mechanisms that are inherent in the social phenomena. In reality, this situation causes intangible and intricate program-working mechanisms. Then, what should we do to explore the impact that a policy has triggered with limited variables? Identifying causal effect through a quasi-experimental method can be one of the answers and quantitative perspective is correctly situated in the criterion.