Gravitational models are currently a commonly used methodology to analyze the behavior of countries' trade flows. These studies typically seek to measure the impact of distance and the size of economies as factors that increase or decrease the propensity to trade between countries. Instead of using the traditional model, this paper introduces two distance variables which are built as modernity factors of culture and productive and institutional apparatus that give some evidence the importance of the economic and institutional stability of the countries to favor trade flows. The new model is tested using historical data of Colombia foreign trade between 1995 and 2015 (which is the most updated year publicly available).

The purpose of this paper is to present the relief operations (RO), responding to a sudden, natural, national disaster (SNND) as a multi-mode resource-constrain multi-project scheduling problem (MRCMPSP). A conceptual framework at a strategic level is constructed and the Colombian RO for an earthquake response is shown as an illustrative case. We concluded that RO can be addressed as a MRCMPSP and that for Colombian case, it is a convenient way to board it. Addressing RO as a MRCMPSP allows managers to implement different project scheduling tools successful in other contexts.