Wouldn't it be preferable to organise metrology by co-operation of national metrology institutes, each of them being responsible for special fields, such as mechanics, electricity, optics, or ionizing radiation? (FAQ - Quantum)
Discussions in Europe under the MERA project (details of which can be found on the EUROMET website) are pointing in the direction of this alternative to a single world or European institute, but some duplication and collaboration will probably always be required for the reasons given in the answer to the previous FAQ. In particular, this model would lead to particular technologies in one country being critically dependent on another country maintaining the facility. Local loyalties could then determine who gets the best calibration service.