The international diffusion of new chemical entities : A cross-national study of the determinants of differences in drug lag

Sammanfattning: The two main objectives of this thesis are to make a general contribution to the understanding of the international diffusion of new chemical entities (NCEs) and to improve the research methods by applying econometric methodology.The study is based on a data base including all 553 NCEs introduced in Sweden during the period 1960-1987 and their introductions in France, West Germany, Italy, the United Kingdom, the United States and Norway. A complementary data base covering 11 countries for the period 1970-1983 is also examined.Large differences are found between the countries regarding the diffusion of NCEs - both in the number of NCEs that are diffused to the countries (level of diffusion) and in the time needed for the NCEs to diffuse (rate of diffusion). There is also a general tendency for an increasing amount of time to be needed for the NCEs to diffuse. Econometric methodology is applied in the search for the determinants of the rate of diffusion. The three earlier models of the rate of diffusion are all rejected and two new models are constructed, one Swedish and one international. In these models the regulation-related variables are found to have the largest influence on the rate of international diffusion of NCEs.At the end of the thesis, policy implications of the results and prospects for the future are discussed.