Rural Development Policies and Sustainable Land Use in the ...

76 CHAPTER 5
Table 5.8—Continued
OLS structural model IV structural model OLS reduced form
Standard Standard Standard
Explanatory variable Coefficient error Coefficient error Coefficient error
Plot characteristics
ln(plot area) –0.17524** 0.08775 –0.28650** 0.13557 –0.31440*** 0.07859
Travel time to residence (minutes) –0.00036 0.00115
Travel time to road (minutes) 0.00291 0.00438
Position on hill (cf. bottom)
Top 0.28868 0.22257 0.29311 0.24655 0.46062 0.29004
Hillside –0.30291** 0.13837 –0.29523 0.19923 –0.33862** 0.16445
Slope (cf. flat)
Moderate 0.40698*** 0.15716 0.33047* 0.19053 0.40648** 0.19344
Steep 0.34977* 0.19735 0.25703 0.24958 0.31614 0.21165
Land tenure)
Percentage of land with title 0.37852 0.25223
Plot tenure (cf. usufruct ownership)
Full title 0.00273 0.26370
Occupied communal land –0.32453 0.34176
Borrowed plot 0.07229 0.16237
Rented/sharecropped plot 0.07311 0.19977
Prior investments on plot
Stone wall –0.06216 0.23110 –0.09600 0.27324 –0.12243 0.26490
Live barrier or fence 0.18327 0.18752 –0.09745 0.17171 0.07861 0.18174
Trees planted 0.17513 0.16283 0.02449 0.19624 –0.16110 0.17488
Intercept 6.56722*** 2.21250 3.91298 2.55770 5.56534** 2.57767
Number of observations 1,164 1,127 1,162
R 2 0.2545 0.1631 0.2528
Wald test of excluded variables p = 0.3947 p = 1.000
Hansen’s J test of overidentifying p = 0.8173
restrictions
Relevance tests of excluded instruments
No burning p = 0.0000***
Minimum/zero tillage p = 0.0000***
Incorporate crop residues p = 0.0000***
Mulch p = 0.0000***
Manure p = 0.0000***
Inorganic fertilizer p = 0.0000***
Herbicide p = 0.0000***
Insecticide p = 0.0022***
Other inputs p = 0.0000***
Family labor p = 0.0000***
Hired wage labor p = 0.0000***
Hired piece labor p = 0.0002***
Hausman test of OLS vs. IV model p = 0.4427 p = 0.1370 c
Note: *, **, *** mean statistically significant at 10%, 5%, and 1% level, respectively.
a
Coefficients and standard errors adjusted for sampling weights and stratification, and are robust to heteroskedasticity and non-independence
of observations from different plots from the same household (clustering).
b
Instrumental variables used in the structural IV model include predicted values of each of the land management practices, input uses, and labor
types from the regressions reported in Tables 5.5 (plus the ones for mulching and manure), 5.6 (plus the one for other inputs), and 5.7 (plus the
variables in the reduced form that were excluded from the structural model).
c
Test of exogeneity of livelihoods and participation in programs and organizations in the reduced form model.