The calibrating role of the inventive concept: a comparative analysis of subject-matter eligibility in India, the United States, and European Patent Convention framework]

Patent systems distinguish ineligible principles from eligible applications using distinct doctrinal devices. This doctrinal, comparative study examines the US ‘inventive concept’, the EPC’s ‘technical character’ (Art. 52), and India’s Section 3 exclusions read with ‘technical effects’. Applying structured content analysis to 25 primary sources (statutes, judicial decisions, and guidance), double-coded (κ = 0.84) and framed by Lijphart’s most-different-systems design, it develops a two-stage ‘calibrated threshold’ model (categorical filter then calibration), operationalised via four criteria – specific technical problem solving, non-pre-emption, tangible output, and non-conventional implementation – and tested on three hypothetical claims. Findings reveal functional convergence rather than doctrinal identity: all filter categorically and calibrate, but devices differ in source, timing and outcomes. Divergence is sharpest for diagnostic/AI claims – likely failing in the United States but surviving under the EPC and in India. India’s Section 3(k) uniquely lacks an ‘as such’ qualifier, creating friction absent elsewhere; no system is uniformly permissive. The model provides a workable analytical lens, with the extension to other systems remaining open. The article advocates coordinated examination guidance to reduce applicant uncertainty, rather than substantive harmonisation of TRIPS-preserved policy choices.