The economic interdependence of contiguous border cities: The twin city multiplier

Twin cities on international borders are common throughout the world. Although located in different countries their economic growth and current levels of income and employment are typically jointly determined through not only each city's basic economic activity but also international trade and resource flows. This paper combines elements of the regional economic multiplier and the foreign trade multiplier models to formulate a twin city multiplier model which shows the levels of income and changes in the levels of income in each border city as a result of changes in economic activity in one twin city.Appreciation is expressed to Ildefonso Guajardo Villareal for his comments on an earlier draft.