Sequential Adoption of Site‐Specific Technologies and its Implications for Nitrogen Productivity: A Double Selectivity Model
分析土壤测试和变量技术两种特定场地技术的序贯采用决策，并评估其对氮生产率的影响。研究发现采用能显著提升低土壤质量农场的氮生产率，但对高质量农场效果不显著。
Abstract This paper analyzes the sequential decision to adopt two site‐specific technologies, soil testing and variable rate technology, and the impact of adoption on nitrogen productivity. The results indicate that while farm location was a key variable influencing adoption of soil testing, farm size, human capital, and innovativeness of farmers had a significant impact on adoption of variable rate technology in four Midwestern states. A double selectivity model applied to correct for sample selection bias shows that adoption leads to significant gains in nitrogen productivity for farms with below average soil quality but statistically insignificant gains for farms with above average soil quality.