When the CLMV countries became members of
ASEAN from the mid-1990s, there had already
existed economic disparities within and between the
six older members. Economic disparity, perceived to
be a hindrance to economic integration, grew larger
within the enlarged grouping with the admission of
the CLMV countries, raising concerns about
difficulties arising out of and now transitioning from
a two-tiered to three-tier regional structure that
includes high, middle, and low incomes countries.