Explore the new relationship between patents and market value: a panel smooth transition regression (PSTR) approach

This paper is the first research applying the new approach, panel smooth transition regression (PSTR) model, in the field of patent analysis. This study uses PSTR model to verify whether there is a single threshold effect of Herfindahl–Hirschman Index of patents (HHI of patents) on the relationship between patents and market value in the American pharmaceutical industry. The results demonstrate that HHI of patents moderates the relationship between market value and patent performance, patent counts/assets and patent citations/assets. When HHI of patents is less than or equal to the threshold value, 0.3220, the positive relationship between patent performance and market value is lower. Once HHI of patents is more than the threshold value, 0.3220, the positive relationship between patent performance and market value is higher. This study points out that the second regime is optimal because the extent of the positive relationship between patent performance and market value is higher.