Which material is better for Earthing Strip (Copper or GI)?

Which material is better for Earthing Strip (Copper or GI):   

        The main objective of earthing is to provide an alternative path for the faulty electricity (fault current) to flow through the ground so that is does not hamper the actual flow of current and ensure the user and gadgets safety.

So, it is very important to select wisely of earthing material especially earthing strip to get a good earthing resistance result. In Bangladesh, copper is used as a earthing strip mostly. But technically and economically, copper strip can be replaced by GI/MS strip. The following reasons are attributed to why GI/MS strip is the perfect alternative of copper strip.

        Conductivity: It is undoubtedly said that cu is a better conductor then GI/MS. If we look into the main purpose of earth electrode, an earth rod is used to provide a physical contact to the earth and provide the most direct path for a current to dissipate. So that in underground, conductivity differences are typically minimal between the most common material.  

        Properties of Earth Resistance: The overall resistance of the earthing depends on the soil resistivity and the condition of the earth location. Hence, selection of material is less important in earth resistance result.

      Chemical Properties: GI/MS are chemically inactive and have a long life. However, cu has a tendency to corrode in humid and saline environments.

          Cost: Cu is a costly metal whereas GI is low costly metal.

So technically and economically, GI/MS is a perfect alternative of copper as earthing material.