Smallholder productivity and weather shocks: Adoption and impact of widely promoted agricultural practices in Tanzania

We investigate the impact of maize-legume intercropping, soil and water conservation practices (SWC), organic fertilizers, inorganic fertilizers and high yielding maize varieties on maize productivity under weather shocks in Tanzania using panel data. First, we estimate the determinants of adoption by applying a multivariate panel data model capturing their complementarities and/or substitutabilities. Second, after testing for their potential endogeneity, we study the impact of these practices (and combinations of them) on maize productivity controlling for weather shocks. Finally, we disaggregate results by presence/absence of seasonal rainfall and temperature shocks to explore the heterogeneous impact of adoption under weather shocks. We find strong complementarities between agricultural practices both in terms of adoption and yield impacts. Long-run variability in rainfall decreases the adoption of organic fertilizers and increases that of improved seeds. Farmers in areas where the cropping season’s rainfall has been highly variable and temperature has been unexpectedly high have significantly lower maize yields. SWC emerges as one of the most important practices in increasing yields with significant benefits by itself, in combination with other practices, under average weather conditions as well as under rainfall and temperature shocks. Overall, increasing the adoption of SWC appears a promising policy option to buffer food security from increasingly frequent weather shocks in Tanzania.     

Long-term crop productivity response and its interaction with cereal markets and energy prices

Crop yields are endogenous as long as economic agents adjust to permanent changes in expected prices. The literature, however, does not offer a definitive value of how much yield would change in response to sustained price changes. To fill the gap, we use available scientific findings and data to estimate yield elasticities that enable agricultural commodity and food policy analysis. Using a world market model with short- to long-run yield response, we show the impacts of sustained energy price shocks on global cereal supply and demand. The results highlight substantial differences in quantity and price effects depending on the yield elasticities. These results demonstrate the need to recognize yield response when assessing impacts of energy prices or biofuel production on food uses or, more generally, on food security in the face of income and population growth, evolving dietary patterns, climate change implications, or other long-run pressures.     

Evidence of slowing yield growth – The example of Swiss cereal yields

We analyze trends in crop yields and yield variability of barley, maize, oats, rye, triticale and wheat in Switzerland from 1961 to 2006. It shows that there have been linear increases in crop yields since the 1960s. However, yields of barley, oats, rye, triticale and wheat have leveled off in Switzerland since the early 1990s, which contrasts linear trends in cereal yields that is usually assumed for Europe. We show a relationship between the introduction of agricultural policy measures towards environmentally friendly cereal production that fostered widespread adoption of extensive farming practices and the observed leveling-off of crop yields. Thus, this paper emphasizes that agricultural policy can be an important reason for slowing crop yield growth. Agricultural policy measures will be one of the key driving forces of future crop yields. Thus, the potential leveling-off of crop yields that is indicated in this study should be considered in analyses of future land use and food supply as well as in the evaluation of agri-environmental measures and policy reforms.     

Estimating impact of cassava research for development approach on productivity,uptake and food security in Malawi

Cassava in Malawi is the second most important staple food crop after maize. This paper assesses the impact of agricultural research for development approach in Malawi on cassava yields, per capita area planted to cassava and household calorie intake from cassava and maize. Given the growing interest over the past decade in agricultural research for development as an innovation systems approach for improving the delivery of research-derived benefits to smallholder farmers and having impact in Africa, this paper provides empirical evidence as to the effects of this framework. The paper concludes that Malawi’s cassava research for development has contributed to measurable gains in area planted to cassava, cassava yields and household caloric intake.     

Examining the link between food prices and food insecurity: A multi-level analysis of maize price and birthweight in Kenya

In developing countries where many poor people rely on rainfed, locally produced food for the majority of their caloric intake, shifts in climate and weather patterns can dramatically reduce agricultural productivity. The reduction in agricultural productivity reduces overall food availability and ultimately impacts food accessibility, putting millions of people at risk for malnutrition. In this project we focus on Kenya where roughly a third of households are food insecure. We examine the relationship of the price of maize and low birth weight to help quantify the impact of local food prices on one outcome of household food insecurity. Using spatially referenced data from recent Kenyan Demographic and Health Survey datasets, price data, livelihood information, and a remotely sensed-based measure of local growing season productivity, we develop a dataset linking pregnancies occurring from 2001 to 2008 to the spatially and temporally relevant maize price data. We construct several regression models to examine the impact of local maize prices and remotely sensed based estimates of crop production on infant birth weight – specifically low birth weight. The results of the models highlight the importance of including community crop production to evaluate maize price impacts on low birth weight outcomes. Also, because of the positive correlation between pre-pregnancy maize prices and birth weight, the results suggest that some households may benefit from high prices or that high prices may impact the number of conceptions. More generally, our work demonstrates that multilevel models that account for community-level variation are important for disentangling these complex relationships and can contribute to the discussion of how to design more effective food policies.     

Compounding food and income insecurity in Yemen: Challenges from climate change

This paper provides a model-based assessment of local and global climate change impacts for the case of Yemen, focusing on agricultural production, household incomes and food security. Global climate change is mainly transmitted through rising world food prices. Our simulation results suggest that climate change induced price increases for food will raise agricultural GDP while decreasing real household incomes and food security. Rural non-farm households are hit hardest as they tend to be net food consumers with high food budget shares, but farm households also experience real income losses given that many of them are net buyers of food. The impacts of local climate change are less clear given the ambiguous predictions of global climate models (GCMs) with respect to future rainfall patterns in Yemen. Local climate change impacts manifest itself in long term yield changes, which differ between two alternative climate scenarios considered. Under the MIR scenario, agricultural GDP is somewhat higher than with perfect mitigation and rural incomes rise due to higher yields and lower prices for sorghum and millet. Under the CSI scenario, positive and negative yield changes cancel each other out. As a result, agricultural GDP and household incomes hardly change compared to perfect mitigation.     

Food price seasonality in Africa: Measurement and extent

Everyone knows about seasonality. But what exactly do we know? This study systematically measures seasonal price gaps at 193 markets for 13 food commodities in seven African countries. It shows that the commonly used dummy variable or moving average deviation methods to estimate the seasonal gap can yield substantial upward bias. This can be partially circumvented using trigonometric and sawtooth models, which are more parsimonious. Among staple crops, seasonality is highest for maize (33 percent on average) and lowest for rice (16½ percent). This is two and a half to three times larger than in the international reference markets. Seasonality varies substantially across market places but maize is the only crop in which there are important systematic country effects. Malawi, where maize is the main staple, emerges as exhibiting the most acute seasonal differences. Reaching the Sustainable Development Goal of Zero Hunger requires renewed policy attention to seasonality in food prices and consumption.     

Viewpoint: Climate impacts on agriculture: Searching for keys under the streetlight

This paper provides a critical assessment of the literature estimating the consequences of climate impacts in agriculture and the food system. This literature focuses overwhelmingly on the impact of elevated CO2 concentrations in the atmosphere, higher temperatures and changing precipitation on staple crop yields. While critically important for food security, we argue that researchers have gravitated to measuring impacts ‘under the streetlight’ where data and models are plentiful. We argue that prior work has largely neglected the vast majority of potential economic impacts of climate change on agriculture. A broader view must extend the impacts analysis to inputs beyond land, including the consequences of climate change for labor productivity, as well as for purchased intermediate inputs. Largely overlooked is the impact of climate change on the rate of total factor productivity growth and the potential for more rapid depreciation of the underlying knowledge capital underpinning this key driver of agricultural output growth. This broader view must also focus more attention on non-staple crops, which, while less important from a caloric point of view, are critically important in redressing current micronutrient deficiencies in many diets around the world. The paper closes with numerical simulations that demonstrate the extent to which limited input and output coverage of climate impacts can lead to considerable underestimation of the consequences for food security and economic welfare. Of particular significance is the finding that humans in the humid tropics are likely more vulnerable to heat stress than are many of the well-adapted crops, such as rice. By omitting the impact of heat stress on humans, most studies of climate impacts greatly understate the welfare losses in the world’s poorest economies.     

Sustainable intensification among smallholder maize farmers in Ethiopia: Adoption and impacts under rainfall and unobserved heterogeneity

In addition to experimental data, using information collected from farmers is vital to assess the performance of candidate farming technologies. The latter provides the basis for farmers’ assessments and adoption decisions. Using detailed georeferenced plot and household level data from Ethiopia, this paper estimates the impact of a set of sustainability-enhancing agronomic practices on maize yields and implied net maize income with the aid of multinomial endogenous regime-switching regression that corrects for unobserved heterogeneity. The treatments’ effects on yield ranged from 29.5% for the fertilizer-dominant strategy to 88% in the case of fertilizer, maize-legume diversification, and soil and water conservation combinations. Second, while the impacts of the agronomic packages are significant in almost all states of the world, there were considerable heterogeneity effects conditioned on observed rainfall deviations from the historical average with levels effects of up to 92% and heterogeneity effects of 33–64%. The heterogeneous and rainfall-conditioned impacts point to the role of local biophysical modifiers of the impacts of agricultural practices. Investments in context-appropriate adaptation in agricultural research and extension is suggested.     

How does population density influence agricultural intensification and productivity? Evidence from Malawi

This article uses nationally representative household-level panel data from Malawi to estimate how rural population density impacts agricultural intensification and household well-being. We find that areas of higher population density are associated with smaller farm sizes, lower real agricultural wage rates, and higher real maize prices. Any input intensification that occurs seems to be going to increasing maize yields, as we find no evidence that increases in population density enable farmers to increase gross value of crop output per hectare. We also find evidence that households in more densely populated areas increasingly rely on off-farm income to earn a living, but there appears to be a rural population density threshold beyond which households can no longer increase off-farm income per capita.     

Could farmer interest in a diversity of seed attributes explain adoption plateaus for modern maize varieties in Malawi?

This study uses new data from a household survey (n = 179) in Mulanje District, Malawi to examine whether the observed adoption plateaus for modern maize varieties in Malawi partly reflect farmer interest in a diversity of maize seed attributes. Regression results for the study area indicate that specific attributes of different maize varieties are an important influence on their use. The benefits to growing hybrid maize appear to be yield and drought tolerance. Open pollinated varieties are selected by farmers who value early maturity. Local maize varieties are popular among farm households owing to a number of favourable processing and consumption characteristics: storability, poundability, flour-to-grain ratio, and taste. Further research using nationally representative data is needed to assess whether findings for Mulanje District can be generalized to Malawi as a whole. If future studies agree with the results herein then maize breeding research programs in Malawi should consider a diversity of traits beyond grain yield to encompass the range of production, processing, and consumption attributes that are valued by farmers.     

Food insecurity,poverty and the Malawian Starter Pack: Fresh start or false start?

Chronic food insecurity and chronic poverty are closely related in Malawi. Since independence in 1964 national food security has been a key policy objective. However, until the 1990s less emphasis was placed on the household dimensions of food security and its links with chronic poverty. In the last decade a number of initiatives have been used in Malawi to tackle the issue of household food insecurity. One of the most controversial has been the Starter Pack programme launched in 1998. Initially consisting of a free handout of packs of improved maize seed, legumes and fertiliser to every small holder farm household in Malawi the scheme, under donor pressure, was subsequently scaled down to become a form of targeted social safety net programme. This paper analyses the strengths and weakness of both the original programme and its scaled down version and assesses the reason for the considerable opposition to the programme from Malawi’s donor community. Although Starter Pack is no longer operative in Malawi the Malawian experience is used to derive lessons for other countries where household food insecurity is an important dimension of chronic poverty.     

Can agricultural input subsidies reduce the gender gap in modern maize adoption? Evidence from Malawi

Nationally representative data for Malawi were used to measure the gender gap in adoption of modern maize and to investigate how, if at all, Malawi’s Farm Input Subsidy Program (FISP) has impacted the gap. Regression results show the probability of adopting modern maize was 12% lower for wives in male-headed households, and 11% lower for female household heads, than for male farmers. Receipt of subsidized input coupons had no discernible effect on modern maize adoption for male farmers. Receiving a subsidy for both seed and fertilizer increased the probability of modern maize cultivation by 222% for female household heads, suggesting the FISP has likely reduced the gender gap in adoption of modern maize in Malawi.     

Impact of tissue culture banana technology on farm household income and food security in Kenya

While tissue culture (TC) technology for vegetative plant propagation is gradually gaining in importance in Africa, rigorous assessment of broader welfare effects for adopting smallholder farm households is lacking. Using survey data and accounting for selection bias in technology adoption, we analyze the impact of TC banana technology on household income and food security in Kenya. To assess food security outcomes, we employ the Household Food Insecurity Access Scale (HFIAS) – a tool that has not been used for impact assessment before. Estimates of treatment-effects models show that TC banana adoption, combined with improved crop management, causes considerable increases in farm and household income. Technology adoption also reduces relative food insecurity in a significant way. These results indicate that TC technology can be welfare enhancing for adopting farm households. Adoption should be further promoted through upscaling appropriate technology delivery systems.     

Does a cassava research-for-development program have impact at the farm level? Evidence from the Democratic Republic of Congo

This paper evaluates the impact of a cassava research-for-development program on farm level outcomes. The program was implemented in the Democratic Republic of Congo from 2001 to 2009. We apply propensity score matching, Rosenbaum bounds on treatment effects, Altonji et al. method of selection on observables and unobservables and endogenous switching regression to farm survey data collected during the 2009 cropping season. We use these methods to test whether the R4D program has a statistically significant effect on outcomes of interest and if these are not driven by selection on unobservables. Using propensity score matching, we find statistically significant positive effects on household participation in cassava markets, adoption of improved varieties and crop management practices and household food adequacy; and no statistically significant effects on yields and profits. The results show that bias due to selection on unobservables is not severe enough to invalidate the impact estimates. Bias may still be a problem that is present in the analysis. But there is evidence that it is not substantial. Although the program does not have a statistically significant positive effect on yields and profits, the significant program effects on market participation, variety adoption, and food adequacy merit further promotion of the program since these positive outcomes tend to be pre-conditions for realizing long-term yield and profit benefits.     

Feeding the famine? American food aid and the GMO debate in Southern Africa

The inclusion of genetically modified maize in food aid shipments to Southern Africa during the 2002 food crisis rekindled debates over agricultural biotechnology. As the region edged ever closer to famine – putting the lives to some 14 million Africans at risk – corporate pundits, government officials and biotech’s critics debated the health and environmental dangers posed by the new technology.By situating the decision to send genetically modified maize to Southern Africa in the context of US–European debates over agricultural biotechnology, it becomes clear that the promotion of biotechnology has nothing to do with ending hunger in the region. Indeed, American food aid shipments to Southern Africa have little to do with the famine at all. Instead, I argue that US food aid policy following the 2002 crisis was intended to promote the adoption of biotech crops in Southern Africa, expanding the market access and control of transnational corporations and undermining local smallholder production thereby fostering greater food insecurity on the Continent.     

The effect of household wealth on the adoption of improved maize varieties in Zambia

Production and price risks that could render input use unprofitable sometimes prevent rural households from benefiting from input technological change. The household’s ability to cope with such risks and hence benefit from input technological change is often positively related to its wealth or stock of productive assets. Empirical evidence, however, suggests a non-linear relationship between wealth and adoption of new agricultural technologies so that within a rural community, households on the lower wealth continuum behave differently from those on the higher level. Using farm level data collected from 300 randomly selected households in three districts of Zambia in 2004/2005 crop season, this paper first stratifies households into poorly- and well-endowed households based on their access to productive assets and estimates separate double-hurdle models for the adoption of improved, high yielding maize (IHYM) varieties for each group. The results show that factors influencing the adoption and use intensity of IHYM varieties differ between the two groups. This draws attention to the need for recommending wealth group-specific interventions to increase the adoption and use intensity of such varieties and their subsequent impacts on food security and general livelihoods of the households. The explicit testing for the possibility that differences in household wealth affect the way in which other variables influence adoption decisions is the paper’s unique contribution to the adoption literature.     

Adoption of improved wheat varieties and impacts on household food security in Ethiopia

This article evaluates the impact of the adoption of improved wheat varieties on food security using a recent nationally-representative dataset of over 2000 farm households in Ethiopia. We adopted endogenous switching regression treatment effects complemented with a binary propensity score matching methodology to test robustness and reduced selection bias stemming from both observed and unobserved characteristics. We expand this further with the generalized propensity score (GPS) approach to evaluate the effects of continuous treatment on the response of the outcome variables. We find a consistent result across models indicating that adoption increases food security and farm households that did adopt would also have benefited significantly had they adopted new varieties. This study supports the need for vital investments in agricultural research for major food staples widely consumed by the poor, and efforts to improve access to modern varieties and services. Policies that enhance diffusion and adoption of modern wheat varieties should be central to food security strategies in Ethiopia.     

Agricultural technology adoption and household welfare: Measurement and evidence

Previous studies on the adoption and impacts of improved crop varieties have relied on self-reported adoption status of the surveyed households. However, in the presence of weak variety maintenance and poorly functioning seed certification system, measurement errors in self-reported adoption status can be considerable. This paper investigates how such measurement errors can lead to biased welfare estimates. Using DNA-fingerprinting based varietal identification as a benchmark, we find that misclassification in self-reported adoption status is considerable, with significant false negative and positive response rates. We empirically show that such measurement errors lead to welfare estimates that are biased towards zero and substantially understate the poverty reduction effects of adoption. While the empirical evidence suggests attenuation bias, our theoretical exposition and simulations demonstrate that upward bias and sign reversal effects are also possible. The results point to the need for improved monitoring of the diffusion process of improved varieties through innovative adoption data collection approaches to generate robust evidence for prioritizing and justifying investments in agricultural research and extension.     

Potential impacts of increasing average yields and reducing maize yield variability in Africa

This study evaluates the potential impacts of investing in Drought Tolerant Maize (DTM) in 13 countries of East, South and West Africa. The analysis utilizes geo-referenced production data at the regional and household levels and employs a model that estimates both the conventional mean yield gains and the additional benefits from yield stability gains of DTM varieties as well as impacts on poverty. The results indicate that by 2016, adoption of DTM can generate between US$ 362 million and US$ 590 million in cumulative benefits to both producers and consumers. Yield variance reductions stand to generate considerable benefits, especially in high drought risk areas. These benefits translate into poverty reductions in the range of 0.01–4.29% by 2016. Significant benefits are also found among different types of households living in drought risk areas of Kenya, Ethiopia and Nigeria.