Growth and convergence under uniform and varying rate of change of technology

This paper seeks to extend the debate on growth and convergence by estimating growth equations which allow for varying rate of change in technology (TFP) as well as the standard assumption of uniform rate. Rate of change of TFP is proxied using an index of patent protection. The dataset used in the paper includes 25 high income countries, 20 middle income countries, 28 low income countries and 16 countries which have transitioned across income categories during the time period considered in this paper. The results of the paper, estimated using the Generalized Method of Moments approach, show significant differences when the rate of change of TFP is assumed to be varying as opposed to being uniform. Significantly, the rate of convergence differs significantly across the subgroups of countries under the assumption of varying rate of change of TFP. Rates of convergence under the assumption of varying rates are clearly higher than those under the uniform rate for high income countries while the results for countries in other income categories are mixed. Key words: Economic growth, Convergence, Patents, TFP, Panel data.JEL: O47, C33. Rast i konvergencija pod jedinstvenom i promenljivom stopom promene tehnologije Rad ima za cilj da prosiri debatu o rastu i konvergenciji procenjivanjem jednacina rasta koje omogucavaju razlicitu stopu promene tehnologije (TFP), kao i standardnu pretpostavku o jedinstvenoj stopi. Stopa promene TFP-a je precizirana pomocu indeksa zastite patenta. Podaci korisceni u radu ukljucuju 25 zemalja sa visokim dohotkom, 20 zemalja sa srednjim dohotkom, 28 zemalja sa niskim dohotkom i 16 zemalja kod kojih je u posmatranom vremenskom periodu doslo do promene kategorije dohotka. Rezultati rada, koji su procenjeni koriscenjem pristupa generalizovanog metoda momenata (GMM), pokazuju znacajne razlike kada stopa promene TFP-a varira, u odnosu na situaciju kad je jedinstvena. Stopa konvergencije se znacajno razlikuje u podgrupama zemalja pod pretpostavkom da stopa promene TFP-a varira. Stope konvergencije pod pretpostavkom o varirajucim stopama su ocigledno vece od onih pod jedinstvenom stopom za zemlje sa visokim dohotkom, dok su rezultati za zemlje u drugim kategorijama dohotka mesoviti. Kljucne reci: Ekonomski rast, konvergencija, patenti, TFP, panel podaci.