As preferential trade agreements (PTAs) have grown in their scope and complexity, so too has the need
to capture this heterogeneity in assessments of their effects. This paper demonstrates an approach for
estimating the effects of “deep” PTAs that allows for non-linear impacts from increased depth. It finds that
deeper PTAs can increase trade but that there are diminishing—and eventually negative—marginal returns
from adding additional policy provisions. This finding fits the observation that certain deep policies may
represent new frictions to trade rather than facilitation efforts. To illustrate the potential trade and welfare
gains that can be attained by increasing the depth of shallow PTAs, a series of counterfactual simulations
are undertaken using the Agadir agreement between Egypt, Jordan, Morocco, and Tunisia as an example.
The counterfactual analysis suggests that increasing the depth of the relatively shallow Agadir agreement
could increase trade between its members by about 13 percent and the value of their real manufacturing
outputs by up to 0.03 percent. Notably, the exercise demonstrates that the optimal version of an agreement
is not necessarily the deepest.
Keywords: International trade, trade agreements, non-tariff measures, gravity, general equilibrium