Bifurcation detection method applied to international intellectual property rights time series data

The US changed its patent policy toward pro-patent-ism in 1980s. Japan discarded one of dual IP (Industrial Property) infringement resolution systems in 1960. Korea adopted material (composition of matter) patent in 1987. These 3 break cases can be detected by iteratively moving “QLR”(Quandt Likelihood Ratio)(Quandt, 1960) tests through using patent or the like time-series data. 1st, using Stata command “varsoc”, we can select the lag-orders for the level data themselves or the natural log data thereof. We may have to use the difference data from the above data. The selection criteria are FPE, AIC, HQIC, SBIC. 2nd, using Stata the command “cusum6”, we can select the appropriate & final model from the above candidate models. Selection criteria are the cumulative sums(CUSUM) of the recursive residuals and their squares from the above models’ regressions. 3rd, in applying the general regression to the time series data we tend to exaggerate the both ends and so should adopt the centered 70% range. The dummy variable “di” indicates the point of the break. The multiplications of independent variables of the above final model by the dummy variable “di” are required for the above QLR test coding contents.