A Regional Model of Endogenous Growth with Creative Destruction

We examine endogenous growth through vertical innovations in a two region model with partial regional and varietal knowledge spillovers. This paper extends the growth literature by adding a regional endogenous growth model with improvements in product quality, instead of a product variety engine for growth, where we account for partial knowledge spillovers in R&D. Starting with the quality ladders endogenous growth model we add traditional goods production by unskilled workers, location as a factor in R&D spillovers, migration of knowledge workers and vary the freeness of trade. Production of each manufactured variety is contestable through vertical innovation based on available knowledge and as a result, firms choose a location to maximise the productivity of R&D, maintain their niche monopoly and minimise transport costs. With contestability, knowledge spillovers provide for additional growth and the partial nature of spillovers causes an additional clustering effect encouraging agglomeration. Growth is highest when there is full agglomeration in one location, as knowledge spillovers are greater with manufacturing concentration. Agglomerated locations are reliant on local inter-varietal knowledge spillovers for growth while peripheral locations rely on trade and regional knowledge spillovers. In the long run, locations experience equal growth rates. If a location becomes agglomerated, it has higher long-run wages and higher growth rates during the transition to the long run. The model offers policy implications for lagging economies to improve inter-regional knowledge spillovers while agglomerated economies should be more concerned with business interaction within the region. Policies which reduce barriers to migration will increase long run growth rates by accelerating the transition to agglomeration.