The effect of mergers and acquisitions on the performance of insurance companies

This thesis investigates the impact of mergers and acquisitions (M&A) on the performance of non-life insurance companies in Türkiye by employing a Difference-in-Differences (DiD) methodology based on firm-level financial metrics. Two major cases are analyzed—Allianz's acquisition of Yapı Kredi Sigorta and HDI'S acquisition of Ergo Sigorta—across four dependent variables: Growth, Return on Assets (ROA), Return on Equity (ROES), and Combined Ratio. The dataset covers five years pre- and post-transaction for two non-life M&A events (2014; 2019), with a carefully screened control group to mitigate confounding. The descriptive statistics initially suggest improvements in Growth, ROA and ROE in the post-merger period: however, these changes do not hold under formal econometric testing, indicating that they may reflect broader industry or macroeconomic dynamics rather than merger-specific effects. The only statistically significant impact is observed in the HDI & Ergo case for the Combined Ratio, where the merger appears to have contributed to enhanced underwriting efficiency. These findings underscore the heterogenous and context-dependent nature of M&A outcomes in the Turkish insurance sector. This study contributes to strategy and insurance economics by (i) focusing on firm-level outcomes in an emerging market, (ii) using a quasi-experimental Difference-in-Differences design, and (iii) triangulating descriptive patterns with inferential tests. The dataset covers five years pre- and post-transaction for two non-life M&A events (2014; 2019), with a carefully screened control group to mitigate confounding. Results highlight that statistically significant improvements are rare; only underwriting efficiency (Combined Ratio) improves in one case, underscoring the importance of moving beyond descriptive trends to credible identification.