将下面改写的学术、精炼一点Although technological catch-up is the mechanism path for HIC to improve input-output efficiency its effectiveness needs to meet certain preconditions so R&D investment and enterprise sca

Technological catch-up serves as the pathway for high-income countries (HIC) to enhance input-output efficiency. However, its effectiveness relies on specific prerequisites, which are represented by the threshold variables of R&D investment and enterprise scale in models 5 and 6.