عنوان مقاله [English]
نویسندگان [English]چکیده [English]
Due to considerable changes in the consumer demand and rising competition in the world markets, firms are under the intensive pressure to maintain their competitive power in the long run by innovation. Clearly, accessing innovation is possible only through research and development activities. Therefore persuation of R&D in firms and recognition of factors that influence R&D activities is very important. The purpose of this study is to examine the determinants of probabilityof Research and Development activities in the industrial manufacturing firms of Iran using Heckman and Tobit regression models and Survey Data Collected by statistical center of Iran in 2008. The results of Heckman and Tobit models estimation indicates that R&D intensity in firms have positive correlation with firm size, ownership dummy, market concentration, human capital and profitability of firms. However export variable has not significant effect on ofResearch and Developmentactivities.