Therefore, employers who have tax equalization programs generally agree to pay both the employers` and workers` share of the host country`s social security taxes on behalf of their transferred employees. The first international agreement in the field of social security was concluded in 1827 between the Grand Duchy of Parma and France. Despite the fact that agreements are aimed at allocating social protection to the country where the worker is most attached, sometimes unusual situations occur, in which strict application of the rules of the agreement would lead to unusual or uneven results. . . .