Driver Individual countries Individual countries Individual countries Across 113 countries Across 113 countries
EKC test Pearson’s correlation coefficient Pearson’s correlation coefficient EKC test Fixed effects model
Number of countries with a U-shape relationship (% of 113 countries) Number of countries with a significant positive relationship (% of the countries with either significantly positive or negative correlation) Number of countries with a significant negative relationship (% of the countries with either significantly positive or negative correlation) Coefficient Coefficient
GDP per capita (linear term) 47 (42%) 3.3925e-05*** 1.2979e-05***
GDP per capita (quadratic term) 5.8554e-11
Consumption per capita for certain crop types 75% for cereal crops, 57% for fruit and vegetable 25% for cereal crops, 43% for fruit and vegetable
Fertilizer to crop price ratio 84% 16% 0.59956***
Per hectare spending on agricultural machinery 37% 63%
Patent application per capita 45% 55%
Education expenditure as a percentage of government spending 45% 55%
Agriculture, value added 47% 53%
Ratio of net import of certain crop types 35% for cereal crops, 50% for fruit and vegetable 65% for cereal crops, 50% for fruit and vegetable
Crop mix 48% for cereal crops, 39% for fruit and vegetable 52% for cereal crops, 61% for fruit and vegetable -0.65446 *** for cereal crops
NUE 99% 1% 1.4113***
Adjusted average farm size 59% 41% 0.058155***
Conservation area ratio 73% 27%
P yield 56% 44% 0.00077645***
Accumulated P surplus 62% 38%
Accumulated P residual 81% 19%