TABLE 3

Estimation of Cobb-Douglas Production Function

Variable (dependent variable: Log of gross crop output in KSh)Village Fixed EffectRandom EffectHousehold Fixed Effect
Log of area cultivated0.584*** (18.92)0.570*** (17.33)0.499*** (12.16)
Log of adult equivalence0.053* (1.97)0.064** (2.24)0.090*** (2.52)
Log of agricultural assets0.074*** (7.07)0.075*** (6.98)0.046*** (3.58)
Log of total cost (except for seed)0.030*** (4.02)0.029*** (3.60)0.014 (1.60)
Log of total seed expenditure0.170*** (8.17)0.165*** (7.70)0.119 (5.42)***
Log of household head’s age- 0.475 (0.33)- 0.389 (0.28)0.346 (0.21)
Log of household head’s age squared0.066 (0.37)0.056 (0.32)- 0.051 (0.23)
Household head with primary education0.021 (0.66)0.020 (0.63)- 0.002 (0.05)
Female-headed household ( = 1)- 0.085*** (2.69)- 0.072** (2.50)- 0.051 (0.84)
Death of adult since prior survey ( = 1)0.114 (1.61)0.078 (1.17)0.065 (0.88)
Log of anual rainfall0.419*** (3.82)0.503*** (3.96)0.516*** (4.14)
Lagged log of annual rainfall0.152** (2.59)0.158*** (2.66)0.159*** (2.83)
Distance to extension service0.001 (0.34)-0.000 (0.12)0.000 (0.07)
Distance to motor road0.011 (1.24)0.010 (1.20)0.005 (0.53)
Distance to nearest piped water source- 0.003 (0.95)- 0.002 (0.99)- 0.002 (0.69)
Distance to the nearest electricity supply0.002 (0.62)0.001 (0.41)- 0.000 (0.09)
Population intensity- 0.075* (1.67)- 0.115* (1.88)
Credit constrained ( = 1)- 0.079 (1.12)- 0.078 (1.20)- 0.063 (0.96)
Observations4,6174,6174,617
R-squared0.670.32
  • Note: Standard errors adjusted for clustering effect at village level. Village dummies, year dummies, and their interaction terms were included in the OLS and random effects models. Year dummies and the interaction terms of year and village dummies are included in the fixed effects model. Inverse probability weighting is used to account for potential attrition bias (see methods section for description). KSh, Kenyan shillings.

  • * Significant at 10%;

  • ** Significant at 5%;

  • *** Significant at 1%.