混合双寡头模型下的R&D竞争:不确定性和模仿视角

通过引入模仿参数δ来衡量R&D容易被模仿的程度,对Joanna Poya-go-Theotoky(1998)的研究进行了拓展,验证了其基本结论的稳健性。此外,通过引入二次R&D成本函数,研究发现,混合双寡头与私人双寡头情况下的社会福利的比较是不确定的,除了依赖创新规模P以外,还取决于模仿参数d,即——(1)对于任意的d,创新规模越大,私人双寡头越倾向于占优混合双寡头,混合双寡头仅在创新规模较小的时候可能优于私人双寡头;(2)对于创新规模比较小的R&D,只有同时具备较容易的模仿程度,混合双寡头才会优于私人双寡头;(3)在不完全模仿(d≠1)的情况下,在R&D越来越容易被模仿的过程中,利率越高(低),私人双寡头优于混合双寡头的最低P值先上升(下降)后下降(上升)。     

Tax Law Improvement in Australia and the UK: The Need for a Strategy for Simplification

In both Australia and the UK, programmes are under way to simplify tax legislation by rewriting it. This paper demonstrates that tax simplification is a complicated concept and concludes that sustainable improvement is unlikely to be achieved if reform is limited only to linguistic changes. Tax law is complicated because there are powerful pressures that tend to increase the complexity of modern tax systems and these should also be considered in any simplification programme. In addition, tax simplification may be promoted by the greater use of purposive legislation — that is, legislation drafted in terms of general principles rather than much more comprehensive legislation designed to deal with every likely possibility. The paper examines the progress of the Australian Tax Law Improvement Project and argues that what is needed is a strategy for tax simplification that is incorporated into the process of generating tax policy itself. JEL classification: H20.