The Origins of Ethnolinguistic Diversity
研究了国家内部和国家间民族语言多样性的决定因素，发现区域土地质量和海拔的地理变异是当代语言多样性的根本原因，支持土地禀赋差异导致本地化人力资本和族群形成的假说。
This study explores the determinants of ethnolinguistic diversity within as well as across countries, shedding light on its geographic origins. The empirical analysis conducted across countries, virtual countries, and pairs of contiguous regions establishes that geographic variability, captured by variation in regional land quality and elevation, is a fundamental determinant of contemporary linguistic diversity. The findings are consistent with the proposed hypothesis that differences in land endowments gave rise to location-specific human capital, leading to the formation of localized ethnicities.