Abstract
<title>Abstract</title> <p>This article examines whether Türkiye's European Patent Office (EPO) patent portfolio became more diversified between 2016 and 2025 and whether the observed transformation represented structural convergence with major technology centres. It treats national patent portfolios as observable outcomes of accumulated industrial capabilities and institutional configurations, thereby linking patent analysis to comparative innovation systems. The dataset covers annual EPO applications in 35 technology fields for Türkiye, the United States, China, Japan, South Korea, Germany, France, the United Kingdom, Italy, Spain, and Russia. Two five-year periods, 2016-2020 and 2021-2025, are compared using the Revealed Technological Advantage Index, the Herfindahl-Hirschman Index, normalised Shannon entropy, cosine similarity, and the Finger-Kreinin Index. Exact permutation tests, effect sizes, chi-square tests, and false-discovery-rate corrections complement the portfolio measures. Türkiye's five-year applications rose only from 3,069 to 3,109, while its share of total EPO applications declined from 0.3575 to 0.3168 per cent. Nevertheless, concentration fell and diversity increased. Relative specialisation strengthened in pharmaceuticals, chemical engineering, materials, environmental technologies, and special machinery, but weakened in computer technology, digital communication, telecommunications, audiovisual technology, and semiconductors. Similarity with the Europe-5 increased, whereas similarity with the Asia-3 and the United States declined. The results indicate selective, path-dependent convergence towards Europe's applied industrial profile rather than broad convergence with the digital-electronics frontier. The article contributes to comparative economics by distinguishing diversification from structural convergence and by showing how different innovation-system configurations are reflected in the composition of national patent portfolios. JEL codes: O31; O33; O38; O57; P51</p>