One major problem in this work is the limitation of the quality of data. In
particular, the evaluation of each country's manufacturing technology level
was not considered explicitly. Even though it was introduced in an earlier
paper (Katayama and Hiraki, 1996), the data were obtained through an
arbitrary interviewing process, using a rough-cut statistical tool, i.e. the
analytic hierarchy process (AHP) model. The final limitation of these works is
the restricted scope in terms of their geographical area. As a further extension
of the ASEAN area is expected in the near future, these models must be
enhanced to evaluate its impact by considering not only China but also other
neighbour countries such as Myanmar, Cambodia and Laos.