This research note examines the implications of the modifiable areal unit problem (MAUP) for the measurement of ethnic segregation in Hamburg, Germany, utilizing 2011 census data and a simulation-based approach that incorporates 10 distinct spatial operationalizations. The results indicate that spatially adjusted global segregation estimates demonstrate a marked resilience to MAUP, despite the correlations between German and foreign populations exhibiting pronounced volatility, which undermines the reliability and comparability of the findings. Moreover, local segregation measures are found to be acutely sensitive to scale and zoning choices, particularly in areas distinguished by heterogeneous distributions of characteristics. In contrast, regions exhibiting homogeneous …