Changing the logic in agricultural extension: evidence from a demand-driven extension programme in Kenya

Figures & data

Figure 1. Impact of Plantwise Training on Plant Health Knowledge.

Notes: Figures represent kernel densities of the unadjusted Plant Doctor Assessment total score measured in standard deviations. Each panel represents the year in which the assessment was conducted (baseline in 2014 and two follow-ups, one in 2015 and one in 2017).

Table 1. The Impact of Plantwise Training on Plant Health Knowledge.

	Multiple choice		Structured		Total Score
	(1)	(2)	(3)	(4)	(5)	(6)
Year 2015 = 1	0.49***	0.49***	−0.27***	−0.28***	0.08	0.07
	(0.05)	(0.05)	(0.07)	(0.07)	(0.05)	(0.05)
Year 2017 = 1	0.84***	0.83***	0.91***	0.89***	1.01***	0.98***
	(0.08)	(0.08)	(0.08)	(0.08)	(0.07)	(0.07)
Plant doctor (PD) = 1	−0.13	−0.22	−0.01	−0.12	−0.07	−0.19
	(0.16)	(0.15)	(0.17)	(0.18)	(0.17)	(0.17)
PD * year 2015	0.90***	0.88***	0.56***	0.62***	0.80***	0.83***
	(0.11)	(0.11)	(0.17)	(0.17)	(0.13)	(0.13)
PD * year 2017	0.93***	0.99***	0.36**	0.44**	0.69***	0.77***
	(0.13)	(0.14)	(0.17)	(0.18)	(0.14)	(0.14)
Age (years)		−0.05**		0.00		−0.02
		(0.02)		(0.02)		(0.02)
Female = 1		−0.19		−0.06		−0.13
		(0.13)		(0.10)		(0.12)
Education certificate = 1		−0.04		−0.08		−0.07
		(0.21)		(0.17)		(0.20)
Years in extension		0.05**		0.00		0.03
		(0.02)		(0.02)		(0.02)
Designation:
AAO I		0.12		0.09		0.12
		(0.19)		(0.19)		(0.20)
AAO III		0.91**		0.69**		0.89**
		(0.43)		(0.31)		(0.37)
SAAO		0.30		0.38**		0.39**
		(0.21)		(0.18)		(0.19)
Deployment:
AEO		−0.10		−0.13		−0.14
		(0.15)		(0.14)		(0.14)
CPO		0.07		0.01		0.04
		(0.19)		(0.15)		(0.18)
Field of specialisation:
Horticulture = 1		0.59***		0.41**		0.55***
		(0.18)		(0.16)		(0.18)
Extension = 1		0.36***		0.06		0.21*
		(0.13)		(0.10)		(0.12)
Other = 1		0.01		−0.12		−0.07
		(0.18)		(0.14)		(0.16)
County fixed effects	Yes	Yes	Yes	Yes	Yes	Yes
AEA mean scores (SD)
2014	−0.30	−0.31	−0.24	−0.24	−0.31	−0.31
2015	0.32	0.31	−0.42	−0.43	−0.10	−0.12
2017	0.58	0.59	0.80	0.82	0.81	0.82
R^2	0.25	0.36	0.33	0.40	0.32	0.43
N	603	587	603	587	603	587

Notes: Dependent variables are Plant Doctor Assessment scores measured in number of standard deviations (SD). Designation categories are Associate Agricultural Officer (AAO) I, AAO II, AAO III and Senior Associate Agricultural Officers (SAAO). Deployment categories are Field Extension Officer (FEO), Crop Protection Officer (CPO) and Agricultural Extension Officer (AEO). Cluster standard errors at the extension officer level in parentheses. Significance level: * p < 0.1; ** p < 0.05; *** p < 0.01.

Table 2. Impacts of PW-K on Agroecological Practices – All Crops.

	Crop rotation	Check for plant health problems on a regular basis	Remove volunteer crops	Use trap crops	Avoid chemical drift when spraying pesticides	Prefers chemical pest control	Apply ash	Spray with chillies
	(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)
	Panel A: 12-month wave
Treat	−0.002	0.029	0.001	−0.001	0.015	0.050	−0.012	−0.004
	(0.023)	(0.014)	(0.018)	(0.004)	(0.013)	(0.024)	(0.008)	(0.006)
	[0.887]	[0.191]	[0.887]	[0.887]	[0.527]	[0.191]	[0.389]	[0.852]
Lagged-dependent	0.098***	0.016	−0.016	−0.021***	0.020	0.034*	0.066	0.015
variable (baseline)	(0.031)	(0.020)	(0.037)	(0.008)	(0.021)	(0.019)	(0.055)	(0.026)
Mean [SD]	0.39	0.70	0.79	0.02	0.33	0.52	0.04	0.03
of DV (control)	[0.34]	[0.46]	[0.27]	[0.11]	[0.47]	[0.50]	[0.15]	[0.13]
PC triplets FE	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes
R^2	0.12	0.17	0.10	0.02	0.10	0.13	0.04	0.02
N	2506	2506	2506	2506	2506	2506	2506	2506
	Panel B: 36-month wave
Treat	0.043**	0.035**	0.046**	0.005*	0.053***	−0.062**	0.027**	0.013**
	(0.021)	(0.019)	(0.021)	(0.005)	(0.016)	(0.024)	(0.010)	(0.005)
	[0.028]	[0.042]	[0.025]	[0.087]	[0.001]	[0.018]	[0.018]	[0.018]
Lagged-dependent	0.063*	−0.024	0.066	−0.019***	0.013	−0.006	0.003	0.008
variable (baseline)	(0.036)	(0.021)	(0.041)	(0.006)	(0.019)	(0.023)	(0.029)	(0.022)
Mean [SD]	0.39	0.69	0.82	0.02	0.33	0.49	0.06	0.03
of DV (control)	[0.33]	[0.46]	[0.24]	[0.11]	[0.47]	[0.50]	[0.18]	[0.13]
PC triplets FE	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes
R^2	0.12	0.06	0.07	0.00	0.13	0.11	0.06	0.03
N	2450	2450	2450	2450	2450	2450	2450	2450

Note. Estimations use OLS using data from the baseline and the 36-month follow-up. All dependent variables are indicator variables equal to 1 if farmer implements a given practice. Impacts of indicator variables are percentage points relative to the control group. Robust standard errors clustered at the clinic level in parentheses. Sharpened False Discovery Rate q-values in squared brackets. All estimations control for PC triplet fixed effects and outcome value at baseline. Impact estimates in Panel A are 12-month impact estimates and those in Panel B are 36-month impact estimates. Means correspond to the means of the dependent variable (DV) for the control group at baseline. *p < .10; **p < .05; ***p < .01.

Table 3. Impacts on yields for annual crops, maize and beans.

	Annuals		Maize
	(1)	(2)	(3)	(4)
	Panel A: 12-month wave
Treat	0.077	0.080	0.129	0.121
	(0.073)	(0.075)	(0.063)	(0.064)
Lagged-dependent variable		0.000***		0.000***
(baseline)		(0.000)		(0.000)
Missing lagged-dependent		−0.256***		−0.079
variable		(0.062)		(0.065)
Household head is male = 1		0.188**		0.184*
		(0.094)		(0.098)
Age of head (years)		−0.009***		−0.007**
		(0.003)		(0.003)
Household size		0.001		−0.003
		(0.016)		(0.018)
Head has tertiary education = 1		0.125		0.151
		(0.092)		(0.098)
PC triplets FE	Yes	Yes	Yes	Yes
R^2	0.18	0.21	0.29	0.33
N	3428	3428	1436	1436
	Panel B: 36-month wave
Treat	−0.041	−0.027	0.137**	0.167**
	(0.078)	(0.075)	(0.069)	(0.067)
Lagged-dependent variable		0.000***		0.000***
(baseline)		(0.000)		(0.000)
Missing lagged-dependent		−0.213***		0.017
variable		(0.077)		(0.071)
Household head is male = 1		0.270***		0.241**
		(0.069)		(0.095)
Age of head (years)		−0.007***		−0.005**
		(0.002)		(0.002)
Household size		−0.007		0.004
		(0.017)		(0.017)
Head has tertiary education = 1		0.273**		0.243**
		(0.107)		(0.100)
PC triplets FE	Yes	Yes	Yes	Yes
R^2	0.18	0.21	0.30	0.32
N	3560	3560	1465	1465

Estimations use OLS using data from the baseline and the 36-month follow-up. Dependent variable in columns 1 and 2 is the value of the yields for all annual crops reported. Maize yields are measured as natural log of production in kg over area planted in acres. Impacts for yields is the percentage increase relative to the control group. Robust standard errors clustered at the clinic level in parentheses. All estimations control for PC triplet fixed effects and outcome value at baseline. Impact estimates in Panel A are 12-month impact estimates, and those in Panel B are 36-month impact estimates. Means correspond to the means of the dependent variable (DV) for the control group at baseline. *p < .10; **p < .05; ***p < .01.

Table 4. Impacts on Extension Advice Received and Usefulness - Maize Farmers.

	Received Advice on					Received Useful Advice on
	New seed varieties	Pest control	Fertiliser use	Post-harvest technologies		New seed variety	Pest control	Fertiliser use	Postharvest technology	Pest information improved
	(1)	(2)	(3)	(4)		(5)	(6)	(7)	(8)	(9)
	Panel A: 12-month wave
Treat	0.018	0.048***	0.026	0.005		0.019	0.051***	0.034**	0.007	0.055***
	(0.016)	(0.016)	(0.017)	(0.008)		(0.017)	(0.016)	(0.016)	(0.005)	(0.016)
	[0.22]	[0.22]	[0.22]	[0.37]		[0.32]	[0.25]	[0.33]	[0.25]	[0.22]
Lagged-dependent	0.076**	0.054**	0.065*	0.020		0.061	−0.140	−0.115	0.083	0.056*
variable (baseline)	(0.032)	(0.025)	(0.035)	(0.049)		(0.064)	(0.097)	(0.136)	(0.061)	(0.032)
Mean [SD]	0.13	0.13	0.12	0.01		0.92	0.95	0.96	0.89	0.13
of DV (control)	[0.34]	[0.34]	[0.32]	[0.10]		[0.11]	[0.07]	[0.07]	[0.03]	[0.31]
PC triplets FE	Yes	Yes	Yes	Yes		Yes	Yes	Yes	Yes	Yes
R^2	0.10	0.10	0.09	0.03		0.08	0.09	0.09	0.02	0.14
N	2203	2203	2203	2203		2203	2203	2203	2203	2203
	Panel B: 36-month wave
Treat	0.040**	0.072***	0.029*	0.013**		0.044***	0.074***	0.027*	0.012**	0.051***
	(0.017)	(0.019)	(0.016)	(0.006)		(0.017)	(0.019)	(0.015)	(0.005)	(0.015)
	[0.02]	[0.00]	[0.03]	[0.02]		[0.02]	[0.00]	[0.03]	[0.02]	[0.00]
Lagged-dependent	0.068**	0.082**	0.037	0.032		−0.007	−0.198	−0.013	0.026	0.073**
variable (baseline)	(0.031)	(0.032)	(0.033)	(0.041)		(0.083)	(0.126)	(0.122)	(0.043)	(0.031)
Mean [SD]	0.14	0.11	0.11	0.01		0.92	0.95	0.96	0.89	0.12
of DV (control)	[0.34]	[0.32]	[0.32]	[0.10]		[0.11]	[0.06]	[0.07]	[0.06]	[0.30]
PC triplets FE	Yes	Yes	Yes	Yes		Yes	Yes	Yes	Yes	Yes
R^2	0.07	0.06	0.05	0.05		0.06	0.06	0.05	0.06	0.06
N	2232	2232	2232	2232		2232	2232	2232	2232	2232

Estimations use OLS using data from the baseline and the 36-month follow-up. All dependent variables are indicator variables equal to 1 if advice category was reported. Impacts of indicator variables are percentage points relative to the control group. Robust standard errors clustered at the clinic level in parentheses. Sharpened False Discovery Rate q-values in squared brackets. All estimations control for PC triplet fixed effects and outcome value at baseline. Impact estimates in Panel A are 12-month impact estimates and those in Panel B are 36-month impact estimates. Means correspond to the means of the dependent variable (DV) for the control group at baseline. *p < .10; **p < .05; ***p < .01.

Table A1. Descriptive statistics and baseline balance.

	Means			SM Diff
	Control	Treat 2014	Treat 2015	(2)-(1)	(3)-(2)	N
	(1)	(2)	(3)	(4)	(5)	(6)
Household Size	4.02	4.14	4.09	0.06	−0.03	2,827
% Age between 0 and 5	0.10	0.11	0.10	0.05	−0.04	2,827
% Age between 6 and 12	0.14	0.15	0.14	0.09	−0.07	2,827
% Age between 13 and 18	0.12	0.12	0.12	0.00	−0.00	2,827
% Age between 19 and 35	0.31	0.28	0.29	−0.12*	0.04	2,827
% Age between 36 and 55	0.21	0.22	0.23	0.04	0.02	2,827
% Age between 56 and 70	0.08	0.08	0.08	−0.01	0.01	2,827
% Age between 70 or more	0.04	0.04	0.04	0.02	0.00	2,827
Language: English	0.04	0.03	0.06	−0.04	0.14**	2,827
Language: Swahili	0.88	0.88	0.85	−0.00	−0.11	2,827
Household head is male	0.81	0.80	0.81	−0.02	0.00	2,827
Household head age	46.11	46.61	47.18	0.04	0.04	2,827
Spouse age	38.81	38.70	38.78	−0.01	0.01	2,118
Head Education: Primary	0.55	0.53	0.54	−0.05	0.02	2,827
Head Education: Secondary	0.37	0.38	0.36	0.03	−0.03	2,827
Head Education: Tertiary	0.08	0.09	0.10	0.04	0.03	2,827
Spouse Education: Primary	0.76	0.75	0.75	−0.03	0.01	2,827
Spouse Education: Secondary	0.22	0.21	0.21	−0.00	−0.00	2,827
Spouse Education: Tertiary	0.02	0.04	0.03	0.09	−0.03	2,827
Household head can read	0.92	0.93	0.92	0.03	−0.01	2,827
Spouse can read	0.90	0.91	0.92	0.03	0.04	2,118
Household head can write	0.86	0.86	0.88	−0.01	0.04	2,827
Spouse can write	0.83	0.81	0.86	−0.05	0.13*	2,118
Roof: Iron sheets	0.92	0.93	0.93	0.03	−0.01	2,827
Walls: timber	0.24	0.29	0.24	0.10	−0.12	2,827
Walls: mud	0.19	0.19	0.20	0.01	0.01	2,827
Walls: concrete brick	0.11	0.09	0.12	−0.04	0.10	2,827
Floor: mud/earth	0.53	0.47	0.48	−0.11	0.01	2,827
Floor: concrete	0.40	0.45	0.43	0.10	−0.03	2,827
Water source: river/lake	0.43	0.36	0.40	−0.15	0.10	2,827
Water source: own tap	0.24	0.32	0.25	0.19	−0.16	2,827
Distance to drinking source	1.72	1.35	0.98	−0.07	−0.07	2,827
Dwelling has electricity	0.25	0.25	0.24	0.02	−0.04	2,827
Energy for cooking: firewood	0.80	0.78	0.80	−0.04	0.04	2,827

Notes: All estimations control for PC triplet fixed effects. SM Diff in column (4) is the standardised mean difference between those assigned to treatment in 2014 and the control group. SM Diff in column (5) is the standardised mean difference between those assigned to treatment in 2014 and those assigned to treatment in 2015. * p < 0.1; ** p < 0.05; *** p < 0.01.

Table A2. Attrition analysis for selected household characteristic.

	Control		Treatment		Differential Attrition
	Mean	NC	Mean	NT	Diff	SE	p-value
Variables	(1)	(2)	(3)	(4)	(5)	(6)	(7)
Household Size	4.11	1,694	4.20	856	0.09	0.17	0.62
% Age between 0 and 5	0.10	1,694	0.10	856	0.01	0.01	0.35
% Age between 6 and 12	0.14	1,694	0.15	856	0.01	0.01	0.27
% Age between 13 and 18	0.12	1,694	0.13	856	0.00	0.01	0.88
% Age between 19 and 35	0.29	1,694	0.27	856	−0.02	0.02	0.20
% Age between 36 and 55	0.22	1,694	0.22	856	−0.00	0.01	0.83
% Age between 56 and 70	0.08	1,694	0.08	856	0.00	0.01	1.00
% Age between 70 or more	0.04	1,694	0.04	856	0.00	0.01	0.69
Language: English	0.05	1,694	0.03	856	−0.02**	0.01	0.03
Language: Swahili	0.86	1,694	0.89	856	0.02	0.03	0.46
Household head is male	0.81	1,694	0.80	856	−0.01	0.02	0.79
Household head age	46.89	1,694	47.14	856	0.25	1.09	0.82
Spouse age	38.97	1,280	39.20	644	0.23	1.09	0.83
Head education: primary	0.20	1,694	0.21	856	0.01	0.02	0.51
Head education: secondary	0.02	1,694	0.02	856	−0.00	0.01	0.98
Head education: tertiary	0.01	1,694	0.01	856	0.00	0.00	0.60
Head can read	0.92	1,694	0.92	856	−0.00	0.02	0.98
Spouse can read	0.91	1,280	0.90	644	−0.01	0.02	0.66
Head can write	0.87	1,694	0.85	856	−0.01	0.02	0.55
Spouse can write	0.84	1,280	0.80	644	−0.04	0.03	0.14
Roof made of: Iron sheets	0.92	1,694	0.93	856	0.01	0.02	0.62
Walls: timber	0.24	1,694	0.28	856	0.04	0.06	0.50
Walls: mud	0.20	1,694	0.20	856	−0.00	0.06	0.95
Walls: concrete brick	0.11	1,694	0.09	856	−0.02	0.02	0.41
Floor: mud/earth	0.52	1,694	0.48	856	−0.04	0.05	0.47
Floor: concrete	0.41	1,694	0.45	856	0.04	0.06	0.47
Water source: river/lake	0.43	1,694	0.36	856	−0.07	0.07	0.33
Water source: own tap	0.24	1,694	0.32	856	0.08	0.07	0.22
Distance to drinking source	1.40	1,694	1.34	856	−0.06	0.34	0.86
Dwelling has electricity	0.23	1,694	0.26	856	0.02	0.05	0.66
Energy for cooking: firewood	0.81	1,694	0.79	856	−0.01	0.04	0.73
Toilet: own pit latrine with slab	0.55	1,694	0.53	856	−0.02	0.04	0.52
Years in farming	18.72	1,688	19.22	854	0.50	1.04	0.63
Years farming this location	15.56	1,688	16.30	854	0.74	0.94	0.43

Notes: Columns (1) to (4) present means and number of observations of baseline household characteristics for the treatment and control groups for observations that were still part of the sample at 36 months. Columns (5) to (7) show results of differential attrition tests. Standard errors clustered at the plant clinic level. Significance level: * p < 0.1; ** p < 0.05; *** p < 0.01.