1 Background
2 Conceptual framework
3 Data collection
3.1 Fieldwork site
3.2 Administration of agricultural training
Location | Category | Total | |||
---|---|---|---|---|---|
Coffee farmers | Cocoa farmers | Both coffee and cocoa farmers | Neither | ||
Hometown (Tanggamus) | 30 | 22 | 15 | 2 | 39 |
Intra-island (South Lampung) | 32 | 22 | 15 | 0 | 39 |
Inter-island (Garut–Ciamis) | 33 | 24 | 17 | 2 | 42 |
Total | 95 | 68 | 47 | 4 | 120 |
Non-cocoa farmers | Cocoa farmers | Total | |
---|---|---|---|
Non-coffee farmers | 4 (3%) | 21 (17.5%) | 25 (20.8%) |
Coffee farmers | 48 (40%) | 47 (39.2%) | 95 (79.2%) |
Total | 52 (43.3%) | 68 (56.7%) | 120 (100%) |
Variables | Coffee farmers | Cocoa farmers |
P value of t-statistics | ||||||
---|---|---|---|---|---|---|---|---|---|
Mean | Std. dev. | Min | Max | Mean | Std. dev. | Min | Max | ||
Demographic characteristics
| |||||||||
Years of experience of cultivating coffee (for coffee farmers) and cocoa (for cocoa farmers) | 17.46 | 11.88 | 0 | 60 | 8.55 | 8.76 | 0 | 40 | 0.000*** |
Years of education of household head | 7.90 | 3.22 | 0 | 16 | 8.42 | 3.24 | 3 | 16 | 0.312 |
Age of household head | 44.27 | 11.30 | 21 | 80 | 44.88 | 9.78 | 28 | 75 | 0.720 |
Cultivated farmland (in Ha) | 1.09 | 0.87 | 0 | 5 | 1.17 | 0.95 | 0 | 5 | 0.578 |
Log of farm income (in Rupiah) | 16.26 | 1.08 | 13.08 | 18.61 | 16.38 | 1.04 | 13.91 | 18.61 | 0.479 |
Mobile phone possession (=1 if owning) | 0.85 | 0.36 | 0 | 1 | 0.81 | 0.40 | 0 | 1 | 0.505 |
Native of Lampung (=1 if yes) | 0.27 | 0.45 | 0 | 1 | 0.26 | 0.44 | 0 | 1 | 0.888 |
Second-generation migrant (=1 if yes) | 0.60 | 0.49 | 0 | 1 | 0.59 | 0.50 | 0 | 1 | 0.899 |
No. of household members | 4.23 | 1.70 | 1 | 12 | 4.27 | 1.73 | 1 | 12 | 0.883 |
Male ratio in the household | 0.55 | 0.16 | 0.25 | 1 | 0.54 | 0.17 | 0.25 | 1 | 0.702 |
Agricultural inputs
| |||||||||
No. of hired labor | 2.87 | 2.22 | 0 | 15 | 3.13 | 2.41 | 1 | 15 | 0.478 |
Annual usage of organic fertilizer (in Kg) | 771.74 | 1079.33 | 0 | 5800 | 792.57 | 1018.07 | 0 | 4500 | 0.901 |
Annual usage of chemical fertilizer (in Kg) | 193.00 | 232.87 | 0 | 1500 | 241.18 | 253.18 | 0 | 1500 | 0.211 |
Annual usage of fertilizer in total (in Kg) | 964.74 | 1184.43 | 0 | 5800 | 1033.7 | 1137.58 | 0 | 4800 | 0.709 |
Information sources
| |||||||||
Knowing extension workers (=1 if yes) | 0.85 | 0.36 | 0 | 1 | 0.84 | 0.37 | 0 | 1 | 0.863 |
No. of agricultural advice network | 5.21 | 2.99 | 1 | 14 | 5.11 | 3.91 | 1 | 20 | 0.853 |
No. of advice network within the farmers group | 3.67 | 2.81 | 0 | 12 | 3.83 | 3.79 | 0 | 19 | 0.757 |
Living nearby extension workers (within 15-min walking distance) | 0.21 | 0.41 | 0 | 1 | 0.24 | 0.43 | 0 | 1 | 0.652 |
Observations | 95 | 68 |
No. | Coffee quiz | Cocoa quiz |
---|---|---|
1 | Characteristics of Robusta coffee and Arabica coffee | Characteristics of the good seedlings for cocoa cultivation |
2 | Characteristics of the good seedlings for coffee cultivation | When to prepare the cocoa nursery |
3 | How to use seeds derived from cutting or grafting | Characteristics of the good seedlings for cocoa cultivation |
4 | The time to prepare shade trees | The time to prepare the shade trees |
5 | How to prepare the planting hole for coffee crops | Suitable crop types for shade trees for cocoa crops |
6 | Characteristics of suitable shade trees for coffee crops | Types of trimmings to form a strong branching of cocoa crops |
7 | Suitable crop types for shade trees for coffee crops | How to manage seedlings and fertilization of cocoa crops |
8 | Suitable crop for inter-cropping (agroforestry) for coffee crops | How to rehabilitate low productivity cocoa crops |
9 | How to perform single stem pruning for coffee crops | Signs of cocoa crops that are ready to be harvested |
10 | How to perform double stem pruning for coffee crops | How to improve productivity of cocoa crops |
Variable | Before training | After training |
P value of t-statistics | ||||||
---|---|---|---|---|---|---|---|---|---|
Mean | SD | Min | Max | Mean | SD | Min | Max | ||
Coffee score | 3.46 | 2.06 | 0 | 8 | 5.92 | 2.42 | 0 | 10 | 0.000*** |
Observation | 95 | ||||||||
Cocoa score | 7.62 | 1.45 | 4 | 10 | 8.73 | 1.53 | 4 | 10 | 0.000*** |
Observation | 68 |
4 Estimation methodology
4.1 Describing social networks
Variables | Coffee farmers | Cocoa farmers |
P value of t-statistics | ||||||
---|---|---|---|---|---|---|---|---|---|
Mean | SD | Min | Max | Mean | SD | Min | Max | ||
Friendship network | 3.54 | 2.22 | 0 | 8 | 3.51 | 2.16 | 0 | 8 | 0.9315 |
Peers advice network | 3.67 | 2.81 | 0 | 12 | 3.83 | 3.78 | 0 | 19 | 0.7569 |
Official advice network | 0.8 | 1.33 | 0 | 5 | 0.69 | 1.34 | 0 | 5 | 0.6044 |
Betweenness centrality | 0.05 | 0.078 | 0 | 0.404 | 0.065 | 0.11 | 0 | 0.679 | 0.3097 |
Closeness centrality | 0.526 | 0.09 | 0.34 | 0.84 | 0.543 | 0.147 | 0.32 | 1 | 0.3623 |
Degree centrality | 0.272 | 0.149 | 0.04 | 0.81 | 0.298 | 0.232 | 0.03 | 1 | 0.3854 |
Observation | 95 | 68 |
4.2 Estimation strategy
Variables | Coffee farmers | Cocoa farmers | ||||||||
---|---|---|---|---|---|---|---|---|---|---|
I | E(I) | SD(I) | Z score |
P value* | I | E(I) | SD(I) | Z score |
P value* | |
Coffee test scores | −0.005 | −0.006 | 0.028 | 0.028 | 0.489 | |||||
Cocoa test scores | −0.047 | −0.008 | 0.040 | −0.974 | 0.165 | |||||
Time × official advice network | −0.007 | −0.006 | 0.027 | −0.049 | 0.481 | 0.033 | −0.008 | 0.039 | 1.063 | 0.144 |
Time × peers advice network | 0.039 | −0.006 | 0.028 | 1.611 | 0.054* | 0.042 | −0.008 | 0.039 | 1.274 | 0.101 |
Time × friendship network | 0.091 | −0.006 | 0.028 | 3.465 | 0.000*** | 0.040 | −0.008 | 0.040 | 1.195 | 0.116 |
Friendship network | 0.423 | −0.006 | 0.028 | 15.312 | 0.000*** | 0.193 | −0.008 | 0.041 | 4.953 | 0.000*** |
Peers advice network | 0.142 | −0.006 | 0.028 | 5.306 | 0.000*** | 0.126 | −0.008 | 0.040 | 3.380 | 0.000*** |
Official advice network | −0.017 | −0.006 | 0.028 | −0.396 | 0.346 | 0.075 | −0.008 | 0.040 | 2.070 | 0.019** |
Years of education of household head | 0.056 | −0.006 | 0.028 | 2.219 | 0.013** | 0.154 | −0.008 | 0.041 | 4.002 | 0.000*** |
Living nearby extension official | 0.138 | −0.006 | 0.028 | 5.136 | 0.000*** | 0.037 | −0.008 | 0.040 | 1.109 | 0.134 |
Motorbike possession | 0.170 | −0.006 | 0.028 | 6.336 | 0.000*** | −0.049 | −0.008 | 0.040 | −1.045 | 0.148 |
Mobile phone possession | −0.068 | −0.006 | 0.028 | −2.249 | 0.012** | −0.095 | −0.008 | 0.040 | −2.156 | 0.016** |
Training outside hometown | 0.184 | −0.006 | 0.028 | 6.772 | 0.000*** | 0.112 | −0.008 | 0.041 | 2.960 | 0.002*** |
No of official attending training | 0.070 | −0.006 | 0.028 | 2.690 | 0.004*** | 0.040 | −0.008 | 0.041 | 1.172 | 0.121 |
Organic fertilizer (=1 if using) | −0.031 | −0.006 | 0.028 | −0.889 | 0.187 | −0.003 | −0.008 | 0.041 | 0.110 | 0.456 |
Chemical fertilizer (=1 if using) | 0.014 | −0.006 | 0.028 | 0.724 | 0.235 | −0.059 | −0.008 | 0.040 | −1.274 | 0.101 |
Years of experience cultivating coffee | 0.019 | −0.006 | 0.028 | 0.906 | 0.182 | |||||
Years of experience cultivating cocoa | 0.148 | −0.008 | 0.040 | 3.896 | 0.000*** | |||||
Time × degree centrality | 0.014 | −0.007 | 0.033 | 0.615 | 0.269 | 0.035 | −0.009 | 0.049 | 0.895 | 0.185 |
Degree centrality | 0.076 | −0.007 | 0.033 | 2.479 | 0.007*** | 0.128 | −0.009 | 0.050 | 2.762 | 0.003*** |
Time × closeness centrality | 0.003 | −0.007 | 0.034 | 0.303 | 0.381 | 0.009 | −0.009 | 0.050 | 0.367 | 0.357 |
Closeness centrality | 0.123 | −0.007 | 0.033 | 3.900 | 0.000*** | 0.145 | −0.009 | 0.050 | 3.117 | 0.001*** |
Time × betweenness centrality | −0.011 | −0.007 | 0.032 | −0.131 | 0.448 | 0.011 | −0.009 | 0.043 | 0.462 | 0.322 |
Betweenness centrality | −0.028 | −0.007 | 0.033 | −0.639 | 0.261 | 0.025 | −0.009 | 0.047 | 0.734 | 0.231 |
5 Estimation results
5.1 Effect of personal networks on learning outcomes
Variables | Coffee score (only for coffee farmers) | Cocoa score (only for cocoa farmers) | ||
---|---|---|---|---|
(1) | (2) | (3) | (4) | |
Time × peers advice network | 0.291*** | 0.290*** | −0.0247 | −0.0243 |
(0.0924) | (0.0922) | (0.0231) | (0.0233) | |
Time × official advice network | 0.123 | 0.124 | −0.295*** | −0.298*** |
(0.235) | (0.236) | (0.112) | (0.112) | |
Time × friendship network | −0.160 | −0.159 | −0.0552 | −0.0539 |
(0.132) | (0.132) | (0.101) | (0.101) | |
Time | 3.136*** | 3.246*** | 2.002*** | 2.044*** |
(0.658) | (0.666) | (0.362) | (0.367) | |
Peers advice network | −0.0742 | −0.0474 | 0.103** | 0.162*** |
(0.0652) | (0.0640) | (0.0443) | (0.0413) | |
Official advice network | −0.163 | −0.286* | 0.0256 | 0.0151 |
(0.151) | (0.146) | (0.128) | (0.118) | |
Friendship network | −0.0253 | 0.0457 | 0.0276 | −0.00968 |
(0.127) | (0.137) | (0.120) | (0.101) | |
Years of education of household head | 0.111* | 0.186*** | ||
(0.0616) | (0.0433) | |||
Living nearby extension Official | 0.0710 | −0.218 | ||
(within 15-min walk) | (0.559) | (0.375) | ||
Organic fertilizer | 1.269*** | −1.310*** | ||
(=1 if using) | (0.480) | (0.385) | ||
Chemical fertilizer | −0.254 | 1.130*** | ||
(=1 if using) | (0.454) | (0.369) | ||
Mobile phone possession | −0.908* | 0.688 | ||
(=1 if owning) | (0.542) | (0.484) | ||
Motorbike possession | 0.888 | 0.551 | ||
(=1 if owning) | (0.637) | (0.406) | ||
Years of experience cultivating coffee | 0.00586 | |||
(0.0182) | ||||
Years of experience cultivating cocoa | 0.00414 | |||
(0.0155) | ||||
Constant | 7.944*** | 5.476*** | 10.11*** | 7.253*** |
(0.596) | (1.178) | (1.339) | (1.590) | |
\(W \times Y_{it}\)
| −0.489*** | −0.530*** | −0.375*** | −0.415*** |
(0.124) | (0.129) | (0.143) | (0.160) | |
Farmers group fixed effects | Yes | Yes | Yes | Yes |
Observations | 172 | 172 | 128 | 128 |
Number of household ID | 86 | 86 | 64 | 64 |
R-squared (within) | 0.524 | 0.525 | 0.484 | 0.483 |
R-squared (between) | 0.240 | 0.352 | 0.265 | 0.465 |
5.2 Effect of network position on learning
Variables | Coffee scores (only for coffee farmers) | Cocoa scores (only for cocoa farmers) | ||||
---|---|---|---|---|---|---|
(1) | (2) | (3) | (4) | (5) | (6) | |
Time × degree centrality | 1.453 | 0.0370 | ||||
(2.022) | (0.719) | |||||
Time × closeness centrality | 1.472 | 0.416 | ||||
(3.363) | (1.223) | |||||
Time × betweenness centrality | 3.879 | 1.397 | ||||
(4.209) | (1.429) | |||||
Degree centrality | −0.0969 | 2.081** | ||||
(1.684) | (0.893) | |||||
Closeness centrality | 0.523 | 3.049** | ||||
(2.906) | (1.458) | |||||
Betweenness centrality | −0.890 | 3.635** | ||||
(3.087) | (1.688) | |||||
Time | 3.842*** | 3.466* | 4.027*** | 1.688*** | 1.483** | 1.631*** |
(0.796) | (1.841) | (0.598) | (0.348) | (0.749) | (0.270) | |
Living nearby extension official | 0.306 | 0.292 | 0.276 | −0.0927 | −0.0828 | −0.313 |
(within 15-min walk) | (0.493) | (0.492) | (0.498) | (0.427) | (0.426) | (0.421) |
Years of education of household head | 0.124** | 0.123** | 0.124** | 0.165*** | 0.169*** | 0.155*** |
(0.0622) | (0.0618) | (0.0605) | (0.0558) | (0.0567) | (0.0527) | |
Motorbike possession | 1.024 | 1.050 | 1.000 | −0.0379 | 0.0126 | −0.367 |
(=1 if owning) | (0.703) | (0.701) | (0.714) | (0.352) | (0.374) | (0.354) |
Mobile phone possession | −0.951* | −0.957* | −0.938* | 0.808 | 0.770 | 0.619 |
(=1 if owning) | (0.495) | (0.492) | (0.488) | (0.550) | (0.577) | (0.590) |
Organic fertilizer | 0.930** | 0.881** | 0.946** | −1.177** | −1.206** | −0.949** |
(=1 if using) | (0.428) | (0.438) | (0.423) | (0.490) | (0.509) | (0.457) |
Chemical fertilizer | −0.658* | −0.648* | −0.655* | 1.206*** | 1.155** | 1.296*** |
(=1 if using) | (0.383) | (0.384) | (0.385) | (0.462) | (0.459) | (0.459) |
Years of experience cultivating coffee | 0.0117 | 0.0116 | 0.0122 | |||
(0.0176) | (0.0176) | (0.0170) | ||||
Years of experience cultivating cocoa | 0.00556 | 0.00392 | 0.00358 | |||
(0.0173) | (0.0172) | (0.0168) | ||||
Constant | 5.994*** | 5.646*** | 6.057*** | 8.184*** | 7.192*** | 9.572*** |
(0.937) | (1.453) | (1.026) | (1.791) | (2.033) | (1.578) | |
\(W \times Y_{it}\)
| −0.598*** | −0.597*** | −0.598*** | −0.450*** | −0.459*** | −0.471*** |
(0.144) | (0.143) | (0.144) | (0.151) | (0.149) | (0.150) | |
Farmers group fixed effects | Yes | Yes | Yes | Yes | Yes | Yes |
Observations | 148 | 148 | 148 | 110 | 110 | 110 |
Number of household ID | 74 | 74 | 74 | 55 | 55 | 55 |
R-squared (within) | 0.475 | 0.472 | 0.479 | 0.454 | 0.456 | 0.461 |
R-squared (between) | 0.400 | 0.402 | 0.399 | 0.474 | 0.460 | 0.489 |