Table 1. Yield losses resulting from a 50% reduction of pesticide use (change from TFI 4.1 to TFI 2.05) estimated with two response functions (log and quadratic) and two statistical methods (quantile regression and stochastic frontier). Yield losses are expressed in t ha⁻¹ and in percentages of the yields obtained with the current level of pesticide use. Results obtained with the quantile regression method are shown for three quantiles (median, and percentiles 20 and 80%). 95% confidence intervals are given in brackets.

Function	Statistical method	Yield loss (t ha−1)	Yield loss (%)
Log	Quantile regression (median)	0.48 (0.26, 0.59)	6.74 (3.84, 8.13)
Log	Quantile regression (percentile 20%)	0.42 (0.28, 0.68)	6.93 (4.7, 11.67)
Log	Quantile regression (percentile 80%)	0.43 (0.3, 0.56)	5.24 (3.84, 6.85)
Log	Stochastic frontier	0.47 (0.34, 0.61)	5.35 (3.9, 6.98)
Quadratic	Quantile regression (median)	0.88 (0.53, 1.06)	12.14 (7.6, 14.28)
Quadratic	Quantile regression (percentile 20%)	0.73 (0.49, 1.05)	11.96 (8.17, 16.44)
Quadratic	Quantile regression (percentile 80%)	0.86 (0.56, 1.03)	10.41 (6.98, 12.5)
Quadratic	Stochastic frontier	0.83 (0.61, 0.98)	10.18 (7.7, 12.29)