1. Introduction
Despite significant gains in poverty reduction in Sub-Saharan Africa (SSA) due to economic growth in the past two decades, rural poverty remains a concern in the region [
1,
2,
3]. Agricultural households comprise a significant proportion of the population trapped in poverty because rural areas are a large harbour of poverty, mainly due to low agricultural productivity. The agriculture sector in the region continues to underperform because farmers rely on unsustainable farming practices that lead to land degradation and poor soil fertility [
4,
5,
6,
7,
8]. Climate change emerges as a major threat to the agriculture sector and might worsen food insecurity and malnutrition in SSA [
9,
10,
11,
12]. Climate change is expected to affect smallholder farmers disproportionately in SSA; for instance, a moderate temperature increase will negatively impact cereal productions such as rice, maize, and wheat, which are mainly produced by smallholder farmers [
13,
14]. Given that many of the countries that will be adversely affected by climate change are in SSA and have a larger share of the poor population, there is an urgent public policy demand for identifying sustainable agricultural practices that can improve welfare and help poor farm households withstand the deleterious effects of climate change.
Due to increases in temperature and changes in rainfall patterns, and lack of structural transformation, the region is at a crossroads and facing a two-fold challenge: (i) to raise agricultural productivity to feed a surging population that is projected to reach 2 billion by 2050, to meet their changing dietary preferences, and alleviating rural poverty [
15,
16]; and (ii) to address the negative consequences of current and projected climate change and strengthen resilience. Given that rain-fed agriculture contributes a considerable share to Africa’s GDP, addressing these challenges is a priority in the current agricultural development policy in the region; it requires a new paradigm to transform African agriculture. The farming systems in SSA are capital deficient, prone to weather extremes, and have poor-quality soils [
5,
13,
17]. Therefore, there is a need to develop and promote technologies and practices that improve resilience and increase agricultural productivity, thereby supporting agricultural transformation [
18]. Sustainable intensification is a unique way forward for African agricultural transformation [
3,
19,
20,
21,
22].
“Climate-smart” agriculture is one of the options for sustainable agricultural production that supports production and enhances adaptive capacity [
15,
23,
24,
25]. Recent agricultural policy has focused on these practices to address economic and environmental concerns [
11,
26]. CSA is an essential component of policy options designed to sustainably increase agricultural productivity, build resilience to climate risks, and mitigate climate change in SSA. It is an example of bundled programs that can have a sustainable impact on poverty because it could be a pathway to resilient escapes from poverty. CSA is also a combination of agronomic innovations that could complement other risk management tools, such as insurance and drought or stress-tolerant seeds, which are often not accessible to the rural poor. However, despite their economic and financial benefits, the uptake of CSA practices among agricultural households remains low. Explanations for this low uptake remain inadequate and unclear, particularly regarding their welfare effect and its complementarity to income risk management options such as non-farm employment.
Studies suggest that high upfront investments, yield uncertainties, and financial constraints are among the major factors that deter farmers’ adoption of CSA in developing countries [
27]. Another strand of the literature comprises studies that establish the link between CSA and welfare [
27,
28,
29,
30,
31,
32,
33]. This study seeks to contribute to this body of literature by analyzing the impacts of CSA on monetary and non-monetary welfare outcome measures, including consumption expenditure, poverty headcount, and multidimensional poverty. Moreover, there is a dearth of evidence on the complementarity between climate risk management strategies, such as CSA, and other non-farm risk management options, such as non-farm employment and migration.
Establishing the link between CSA, non-farm employment, and welfare is important. This is because, without identifying the substitutability or complementarity of farmers’ livelihood options, such as CSA and other income risk management strategies, such as non-farm employment, scaling up CSA practices only goes so far as to improve farmers’ resilience. Establishing the above link is also crucial because rural households in developing countries engage in three complementary pathways out of poverty: (i) the farm pathway that entails growth in agricultural incomes, (ii) growth in non-farm incomes, and (iii) migration. Therefore, this study investigates if CSA would crowd out other income risk management strategies (non-farm employment). This is based on the hypothesis that if risk is a factor for livelihood choice and income growth [
34,
35,
36], climate risk mitigation strategies in agriculture, such as CSA [
2], could complement or substitute other income risk management options, such as non-farm employment.
Our research fills an important gap in the literature by illuminating the link between CSA, non-farm employment, and household welfare. The study evaluates the effects of CSA and non-farm employment (when adopted individually or in combination) on household welfare using nationally representative data from Ethiopia and a Multinomial Endogenous Switching Regression (MESR) model. We find that the impact of combining CSA and non-farm employment guarantees better household welfare compared to the case where a household is not practising CSA or engages in non-farm employment. However, CSA adoption alone appears to provide higher consumption expenditure than its combination with non-farm employment.
The rest of this paper is structured as follows.
Section 2 briefly reviews the literature.
Section 3 discusses the data and presents the descriptive statistics for the variables of interest.
Section 4 presents the estimation strategy.
Section 5 discusses the findings. The last section concludes the study and points out some policy implications of the results.
3. Data
3.1. Household Survey Data
This study uses data from the latest round of the Ethiopian Socioeconomic Survey (ESS) collected under the Living Standards Measurement Study-Integrated Surveys on Agriculture (LSMS-ISA) of the World Bank in collaboration with the Central Statistical Agency (CSA) of Ethiopia. ESS is publicly available rich, georeferenced, nationally representative (at both the urban and rural levels) household survey data. It provides a rich array of information on household characteristics, income sources, household assets, consumption expenditure, shocks, coping strategies, food security, land holdings, crop production, and livestock ownership. The survey collects data on households from 2011 to 2016 in three waves (2011/12, 2013/14, and 2015/16). However, the 2018/19 ESS is a new panel, and hence we could not exploit the panel structure of the data. ESS has an agriculture module that captures detailed information on CSA practices, post-planting, and post-harvest activities, including landholding, crop production and disposition, and livestock ownership. In addition to the household data, the survey solicited community-level information on access to public services, such as infrastructure, markets, and health services. The georeferencing of the households enables us to merge household data with geospatial climate information.
3.2. Climate Data
We merge the household data with temperature and precipitation data obtained from the Climatic Research Unit (CRU-TS-4.03), University of East Anglia [
57]. We use the downscaled version that corrects for bias, which is produced by WorldClim [
58]. The temperature variable measures the average near-surface maximum temperature in degrees Celsius, and the precipitation variable measures total precipitation in millimetres.
The temperature and precipitation data are gridded monthly time-series data for the period between 1960 and 2018 with a spatial resolution of 2.5 min and roughly 21 km. Using this data, we used the households’ GPS coordinates (latitude and longitude) to create a five-kilometre buffer around each point. We then used this five-kilometre buffer to merge the precipitation and temperature data within the buffer for each household. Next, we followed a similar strategy to merge the household data with the Standardised Precipitation Index (SPI) data from University Corporation for Atmospheric Research (UCAR). However, we create a ten-kilomette buffer for the SPI due to data availability. The SPI is used to characterize meteorological drought. On short timescales, such as our context, the SPI is closely related to soil moisture, while at longer timescales, the SPI can be related to groundwater and reservoir storage.
The temperature, precipitation, and SPI are calculated as monthly averages. The monthly average for 2018/19 was taken from July (post-planting) of the survey year to June (post-harvesting). This allows capturing the climate variability span of the post-planting and post-harvesting stages of the LSMS-ISA dataset. We use these variables in the estimation to account for climate variability’s short- and longer-term effects on household livelihood choices.
Figure 1 presents the temperature, precipitation, and SPI data. Existing studies suggest that the welfare effect of climate change (change in temperature and precipitation) takes time [
59], and the indirect effects, such as water scarcity, displacement, uncertainty, and food security, are a substantial threat and can cause long-lasting welfare damage [
60]. Therefore, we include temperature
’s and precipitation
’s in the regressions instead of using the same year average of the climate variables. We also check the effect of one lag temperature and precipitation, the qualitative results remain unchanged. Results are available from authors on request.
3.3. CSA and Non-Farm Employment
Farmers in rural Ethiopia adopt a wide range of CSA practices. We construct an index for CSA adoption using principal component analysis (PCA). PCA is preferred to the additive index because it produces a more effective measure by recovering the underlying latent variable [
61]. To construct the CSA adoption variable, we consider cereal–legume intercropping, zero tillage, natural fertilizers, improved seeds, irrigation, soil conservation, and crop rotation variables that are collected in the ESS. The Kaiser–Meyer–Olkin (KMO) measure of sampling adequacy for the CSA practices we considered is 0.53, supporting the use of PCA for the analysis. The PCA results show that the first three components had eigenvalues greater than one—dominating in terms of eigenvalues and proportion of variance. The components vector also contains positive weights for all the CSA practices, suggesting that the aggregate variation in our score results from household variation in adoption levels [
62]. Thus, we classified households based on the three PCA scores, with PCA scores greater than zero as adopters of CSA and those with less than or equal to zero as non-adopters.
To explore the complementarity (substitutability) of CSA with non-farm employment, we constructed a non-farm employment variable. Non-farm employment is defined at the household level as a binary variable taking a value of 1 if the household participates in (generates income from) wage employment or self-employment (enterprises) or receives a transfer from a migrated household member, 0 otherwise.
Following the above definitions, the treatment indicator or adoption variable is defined as a polychotomous variable with four possible discrete outcomes: (i) none (a household adopted neither CSA nor non-farm employment), (ii) CSA only, (iii) non-farm employment only, and (iv) both (a household adopted CSA and non-farm employment simultaneously).
3.4. Welfare Outcomes
The welfare outcomes include consumption expenditure per adult equivalent per year, monetary poverty (based on the bottom 40% of the consumption expenditure), and a multidimensional poverty index (MPI). The consumption expenditure per adult equivalent value is obtained by aggregating the value of food and non-food spending at the median prices. The median prices are calculated at the lowest geographical unit for which there are at least 10 price observations. If there are less than 10 price observations for that item at the enumeration area (EA), the next level up is used. The geographical levels used, in ascending order, are EA, Kebele, Woreda, zone and region, and national. The aggregate consumption expenditure is adjusted for differences in the nutritional or calorie requirement of different household members by dividing it with an adult equivalence scale. Given that our analysis focuses on rural households and the incidence of poverty is higher in rural areas of Ethiopia, using the national poverty line overestimates the poverty rate. Thus, we used 40% of the average annual consumption expenditure per adult equivalent as a poverty line threshold. Monetary poverty is a binary variable taking a value of 1 if the per adult equivalent expenditure per year is less than the 40th percentile of the annual consumption expenditure per adult equivalent (i.e., Birr 9254) and 0 otherwise. The multidimensional poverty index (MPI) is constructed using three main dimensions (education, health, and living conditions) and nine sub-dimensions following the methodology developed by [
63]. Education and health indicators are weighted 1/6 and 1/3 each, respectively, and the standard of living indicators are weighted 1/18 each. Under education, we considered years of schooling (At least one child aged 7–15 years is not attending school) and school attendance (No one in the household has at least 6 years of education). For the health dimension, we considered whether at least one 6–59-month-old child in the household is stunted. Finally, under living standards, we include access to electricity, access to improved water, access to an improved sanitation facility, access to safe cooking fuel (household does not use solid cooking fuel such as wood, charcoal, leaves, or manure), floor type (household does not have a quality finished flooring) and ownership of assets (household does not have a radio, TV, or phone or no transportation asset and no refrigerator). MPI is a binary variable taking a value of 1 if a household is multidimensionally poor and 0 otherwise.
Households that adopt CSA or participate in non-farm employment have higher consumption expenditures than non-adopters (
Figure 2). There is a statistically significant difference in consumption expenditure between the different groups of households: none (non-adopter), CSA, non-farm employment, and both CSA and non-farm employment. Adopters (of CSA or non-farm employment in isolation or combination) have higher consumption expenditure, on average, than non-adopters. Comparing the livelihood options, households that adopt CSA and participate in non-farm employment have the highest average consumption expenditure, followed by those that participate in non-farm employment only and those that adopt CSA only.
Figure 2 further shows that, on average, female-headed households (FHH) adopting one or both of the livelihood options had a higher consumption expenditure than their male counterparts (MHH).
Figure 3 presents monetary and multidimensional poverty rates by livelihood options and gender of the household head. In line with our observation in
Figure 2, households that adopt the two livelihood options simultaneously have lower monetary and multidimensional poverty rates. Similarly, FHHs that adopt non-farm employment and CSA jointly have the lowest monetary and multidimensional poverty rates.
3.5. Control Variables
The control variables used in the regressions include socioeconomic and demographic characteristics (gender of head, age of head, household size, and head education), wealth (livestock holding and land holding), proximity to services (distance to roads and markets), extension reach, shocks experience, and climate variables. The choice of the variables is based on a review of the existing literature, economic theory, and data availability.
Table A1 in
Appendix A provides the summary statistics of the main explanatory variables used in our analysis by adoption status: none, CSA only, non-farm employment only, and both.
4. Empirical Strategy
The biggest challenge in estimating the effect of non-random self-selected interventions is finding a credible estimate of the counterfactual: what would have happened to treated households, for instance, households that adopt CSA if they had not adopted CSA? If adoption is randomly assigned, the difference in the outcome between CSA non-adopters (untreated households) and CSA adopters (treated households) can be a reasonable estimate of the treatment effect. However, households that adopt that livelihood option may have characteristics that differ from the ones that do not adopt it [
64]. Without information on why households self-select to adopt one or more strategies, the next best alternative is to construct a counterfactual (a comparison group), which is as close as possible tothe treated households; those who adopt CSA and non-farm employment would have had similar outcomes in the absence of the treatment [
64,
65]. We use a multinomial endogenous switching regression model (MESR) that allows deriving the impacts of CSA adoption and non-farm employment on household welfare while addressing selection bias.
Let there be exclusive livelihood options or climate risk management strategies whereby the possible strategies are denoted using . For each household, only one state of the potential strategy is observed, and the other states are counterfactuals. The adoption of a particular strategy (CSA, non-farm employment, or both) is donated by . There are potential outcomes for each household, but there is only a single state strategy that is observed . Thus, for a household , then . In the context we are working, where households adopt one or more strategies, we emphasize the comparative efficacy of all strategies jointly and separately.
In this framework, the relative average treatment effect (ATE) of strategy
relative to
is the difference in average outcomes had all households been observed under a single strategy
t versus had all households been observed under the alternative strategy
[
66,
67].
Formally, ATE
is given as follows:
The average treatment on the treated (ATT) is the pairwise contrast of the effects of the strategy and
for households in either
or
. Thus ATT is given in Equation (
2):
The relative ATT of treatment
among households that adopt strategy
is the difference between the mean outcome of those who adopt strategy
and those who adopt
would have had if they had been adopted
instead of
(Araar et al., 2019 [
66]; Wooldridge 2010 [
67]).
In this study, we aim to identify the combination of CSA and non-farm employment that is most beneficial to improving the welfare of farm households. Thus, we estimate and report both ATE and ATT. While ATE sheds light on the gain in welfare (the treatment effect) if all farm households adopt a particular strategy, ATT provides information on the relative effectiveness of one strategy versus another. Therefore, we estimate and report ATE and ATT to provide complete information, as summarized in
Table 1.
A farming household’s choice between CSA and/or non-farm employment or the simultaneous adoption of both may be endogenous to observed and unobserved characteristics of households leading to self-selection bias. As discussed above, to address potential self-selection bias due to observed and unobserved characteristics of households, we use the multinomial endogenous switching regression approach following Dubin and McFadden (1984). Using this approach, we first model the livelihood strategy decision (CSA, a combination of CSA and non-farm employment, or neither) using a multinomial logit selection model that accounts for the interdependence between the strategies. Then, the effects of each strategy on welfare (consumption expenditure per adult equivalent and monetary and multidimensional poverty) are assessed using a linear regression model with endogenous treatment effects.
Let
describe household
i’s choice of CSA and non-farm employment
j over another alternative
p; given as follows.
where
is the vector of observable characteristics of households and their members that affect the choice of CSA and non-farm employment, such as gender of household head, age, education, household size, land size, ownership of livestock, distance to market, access to extension services, temperature, and precipitation.
is the unobservable characteristic that affects the adoption decision of one or more strategies. The utility of adopting an alternative CSA practice is not observed, while the actual adoption of a given practice is observed. A household’s choice of a practice
j over an alternative practice
m is given by:
where
(Bourguignon et al., 2007 [
68]). Equation (
4) implies that household
i chooses alternative practice
j over
m if and only if the welfare gain from
j is greater than that welfare obtained from
m for
.
Assuming that
is an independent and identical distribution, the probability that household
i will adopt a given CSA practice and/or non-farm employment
j given its characteristics
z can be given as a multinomial logit model, as in Equation (
5) [
69].
The following multinomial endogenous switching regressions are specified to evaluate the effect of each livelihood strategy on the welfare of households:
where
,
,
, and
are the four discrete outcomes representing non-adopters, those that adopt CSA only, non-farm employment only, and both CSA and non-farm employment, respectively.
is the vector of observable characteristics that affect the choice of CSA and non-farm employment, such as gender of household head, age, education, household size, land size, livestock ownership, distance to market, access to extension services, and climate variables.
Due to possible confounding factors, such as motivation to work and risk-taking behaviour, that affect the outcome variable in the above equations and the selection equation, estimating the above equations using OLS yields biased results. Hence, consistent estimates of the parameters require correction for selectivity. In addition to the selectivity bias correction obtained from the multinomial logit model (the inverse Mills ratio -IMR terms), we have considered an exclusion restriction variable that is used as the IV. The IV is the village-level CSA adoption rate calculated by excluding the household under consideration to avoid possible reverse causality in that the household’s CSA adoption decision affects the CSA adoption decision at the village level. The basic argument for using the village-level CSA adoption as an IV is that agricultural technology adoption and production decisions are likely to be influenced by the decision of neighbouring households due to peer effects and learning externality [
70,
71]. Farmers in the same neighbourhood face similar demographic, institutional, and economic challenges and thus are likely to adopt similar production systems [
70,
72]. Thus, CSA adoption at the village level will affect the livelihood choice of households. The IV is expected to not be correlated with the unobserved household heterogeneity and the household consumption or poverty status [
71,
72].
According to [
68], consistent estimates of the parameters can be obtained by introducing a correction term in the above equations as follows:
where
is the covariance between
and
u.
is the correction term (the mills ratio given in Equation (
8) below) derived based on estimated probabilities from the first equations (Equation (
5)) and the correlation
between
and
u.
Following this, we can estimate the expected household welfare (consumption per adult equivalent and poverty) for untreated farming households as follows:
Similarly, the expected household welfare of households that adopt the different strategies under investigation are given as follows:
Comparably, the expected value of consumption per adult equivalent or poverty for non-adopters had they adopt one or more strategies is given as follows:
Finally, the expected value of consumption per adult equivalent or poverty for those that adopted
j had they not adopted any of the strategies is given:
and
are treatments in
j ATE and ATT are computed as follows:
6. Conclusions and Policy Implications
Climate-smart agriculture (CSA) has received increasing attention in recent policy dialogues for its potential for agricultural transformation, risk management, and welfare improvement. This study provides evidence on the welfare impacts of CSA adoption and its complementarity with non-farm employment. For this purpose, we estimate the impacts of CSA when adopted in isolation and in combination with non-farm employment on monetary (yearly household consumption expenditure and monetary poverty) and non-monetary (multidimensional poverty index) welfare outcomes using household-level data from Ethiopia combined with novel historical weather data. The study uses a multinomial endogenous switching regression model to deal with selection bias and farmer heterogeneity.
Two results are worth stressing. First, the impact of combining CSA and non-farm employment guarantees better income risk management compared to the case where a household is not practising CSA or engages in non-farm employment. Our result shows that households that adopt both CSA and non-farm employment simultaneously have lower poverty rates than non-adopters. Second, contrary to the first result, CSA adoption results in higher consumption expenditure per year than its combination with non-farm employment (the option that characterizes labour-oriented households), and the wealthiest households earn more on average than the poorest by adopting the two strategies. The labour demand effect could explain our results because CSA and non-farm employment compete for productive household labour. However, taking account of seasonality would help to establish such relationships because farm-oriented households that adopt CSA would engage in non-farm employment or migrate during the off-season when labour demand for farming is at its low.
Overall, our results suggest that, in a country such as Ethiopia, where markets are not complete and institutions are lacking, the adoption of CSA significantly improves rural households’ welfare. Most of the CSA practices we have considered in this study (e.g., zero tillage, natural fertilizer, and other soil fertility management practices) are adopted by households in the lower segment of the income distribution, indicating that they are likely to be adopted by poor rural households. There could, however, be other factors that constrain the adoption of CSA that would lead to suboptimal adoption of CSA. Policies that seek to leverage the welfare benefits of CSA need to acknowledge the capacity of households in CSA adoption and non-farm employment.