Random Effects Analysis Of Influencing Factors Of R&D Investment

Random effects model is widely used in economic,medical,biological,psychological and other fields.In reality,many events are affected by a number of factors,which,according to their own characteristics,can be divided into deterministic and randomized,deterministic factors that are controllable,and stochastic factors are uncontrollable with randomness.The randomness factor is the focus of the stochastic effect model.Factors that affect their R&D investment are random and uncontrollable,so how are these factors influencing the R&D investment.This paper is mainly based on the two-tier random effects model,which studies the factors that affect the R&D investment.We mainly tested the R&D investment whether confronted with financing constraints and government R&D subsidies.Because the financing constraints has a negative effect on the R&D investment?While,R&D investment is positively influenced by government subsidies.These two factors have the characteristics of one-side distribution,so we can base on the two-tier stochastic effect model to analysis the affect of R&D investment.The maximum likelihood estimation method is used to estimate the model,and the maximum likelihood ratio test is used to test the statistics.This paper used sample of hi-tech listed companies which had disclosed R&D investment during 2012-2015 in growth enterprise board.We follow the heterogeneity among different enterprise to conduct a further study.The study found that: in the GEM high-tech listed companies,corporate R&D investment will be subject to government subsidies and increase,so that enterprises have more funds for R&D investment,resulting in a positive effect;and corporate R & D investment will be due to Subject to financing constraints will be reduced,is the corporate R&D investment is inhibited,resulting in a negative effect.And in different samples of the enterprise R&D investment situation is not the same.