There is not, however, any measurement of the restrictiveness of the measure.

A safeguard clause with regard to trigger threshold, with acceptable degrees of restrictiveness and leniency, can be devised.

Indeed, the OECD ranks Japan last among member states in terms of regulatory restrictiveness with respect to inward foreign direct investment.

They can only be used to construct indicators of trade restrictiveness that in turn can be used to estimate quantity and or price effects.

In addition, economic analysis to complement frequency counts of NTBs should, in particular, focus on the trade restrictiveness and impact of NTBs, especially on developing countries' trade.

Generally speaking, comprehensive estimates of NTBs' impacts, in particular price impacts, could then be used to construct sound trade restrictiveness indicators, as done by Kee, Nicita and Olarreaga.

In addition to information concerning the frequency of NTBs, they also make it possible to gather data on the relative importance of different measures, such as their trade restrictiveness or trade impact.

With this information in hand, it would be possible to use it to construct sound trade restrictiveness indices and or integrate it into simulation models to deepen the understanding and qualification of the impact of possible policy decisions, especially on developing countries' trade.