| dc.description.abstract | Global demand for food and agricultural products is on the rise. There is hence the need to
increase production to meet this growing demand and smallholders will play a significant
role. One strategy for smallholders to sustainably increase agricultural production is the use
of modern productivity-enhancing technologies such as improved crop varieties. Investments
in global agricultural research have resulted in the development and release of thousands of
new varieties since the first Green Revolution. However, especially in Sub-Saharan Africa,
traditional varieties still dominate smallholder farming, limiting the envisaged output and
productivity gains. Lack of agricultural information is often cited as a major constraint to
adoption of improved varieties, and the role of social networks in diffusion of information
relevant for adoption of these varieties is increasingly being studied.
This research contributes to the growing literature by looking at a number of elements
that to the best of our knowledge have not been studied before. First, most studies on social
network effects in agricultural technology diffusion tend to focus on networks within villages
(intra-village networks). In this study, we look at effects of social networks across villages
(intra-village networks) as well. Furthermore we explore other types of networks, in
particular to community leaders (village administrators), who are part of formal information
dissemination channels. Second, while the role of social networks in cereal farming has been
investigated in the context of well-developed private seed markets, we do not find any studies
assessing the role of social networks in situations where seed markets are underdeveloped.
This study investigates effects of social networks in two contexts: one with developed seed
markets and the other with frequently failing seed markets. Third, studies linking social
networks to new agricultural technologies tend to focus on technology diffusion. However,
information conveyed through social networks might also affect other farming practices and
hence we investigate also the effects of social networks on technical efficiency.
The main objective of this dissertation is to assess social networks and their explicit
role in technology adoption and technical efficiency in smallholder agriculture. Using data
collected from 345 cereal growers in Central Tanzania between September and November
2012, we focus on improved varieties of sorghum and maize, the staple cereals in the study
area. Improved varieties of sorghum in Tanzania are characterized by underdeveloped private
seed markets, while those of maize have mostly functioning private seed markets. This
enabled us to make interesting comparisons that have not been made before. Our specific
objectives are (1) to assess the factors that determine the existence of network links for the exchange of agricultural information between farmers, (2) to examine the role of social
networks in exposing farmers to improved sorghum and maize varieties and hybrids (as a
precondition for adoption of the technologies), (3) to assess the effects of social networks on
adoption of improved varieties, and (4) to investigate the role of social networks for technical
efficiency. In addition to descriptive analyses, a number of econometric tools were developed
and used to achieve the objectives. These include dyadic regressions to identify determinants
of network links, Poisson regressions to assess exposure to improved varieties, and the
average treatment effect (ATE) framework to analyze adoption while controlling for nonexposure bias. To analyze technical efficiency, a stochastic frontier framework was applied.
Propensity score matching techniques were used to control for endogeneity in the stochastic
frontier analysis.
We find that even at the lowest administrative unit, the sub-village, not all farmers
know each other. Interestingly, even in the cases where farmers know one another, only about
one third of randomly drawn pairs of such farmers exchange agricultural information. The
exchange of relevant information is more likely between farmers who have similar levels of
education, different farm sizes, are members of the same community association, live in the
same village, have known each other for a longer time, have kinship ties, and if one of them
is a community leader or has a direct link to a public extension officer. These patterns are
almost the same for sorghum and maize, meaning that if farmers exchange farming
information, they are unlikely to limit this exchange to certain crops.
Farmer-to-farmer networks are important sources of first information on improved
sorghum and maize varieties, with neighbors and friends playing a bigger role than relatives.
Moreover, controlling for other farmer characteristics, we find that increasing the size of a
farmer’s network increases the farmer’s intensity of exposure (number of varieties known) to
improved varieties of sorghum, but not to those of maize. Further disaggregation of maize
varieties shows that while larger social networks increase farmers’ exposure to open
pollinated varieties (OPVs), the result remains insignificant for hybrids. Seed markets for
hybrids are more developed than those of OPVs. Hence, the flow of information through
informal networks is more important for seed technologies for which formal markets fail.
Strikingly, inter-village networks play a larger role in creating awareness about new varieties
than intra-village networks. Other results show that by networking with public extension
officers and village administrators, farmers increase their exposure to improved varieties
considerably. We conclude that informal information channels complement, but do not
substitute awareness creation through formal channels.Consistent with expectations, we find evidence that for both crops, lack of exposure is
indeed a constraint to the adoption of improved varieties, signaling a need to create more
awareness. Interestingly, even after accounting for the role of social networks in exposure,
and controlling for the intensity of exposure, we find that social networks for sorghum have a
positive effect on variety adoption. We do not find significant social network effects on
adoption of improved maize varieties, implying that the influence of social networks on
adoption is greater for improved varieties whose markets often fail. Contrary to the influence
of social networks on exposure, it is the intra-village and not inter-village networks that
produce this effect in the case of sorghum. It means that while inter-village networks are
more important for learning about new varieties as shown above, intra-village networks play
a more important role in adoption. Network links with village administrators or extension
officers do not influence adoption significantly, meaning that in the adoption process, formal
channels are more relevant for the first step, which is, raising awareness.
Finally, while the total and intra-village network sizes do not significantly influence
technical efficiency, the inter-village sorghum network size has a positive effect on technical
efficiency of improved but not of traditional varieties of sorghum. When comparing between
improved varieties of the two crops, we conclude that social network effects are more
relevant for varieties that do not have functioning private seed markets, consistent with the
findings for exposure and adoption. Networking with village administrators did not have any
significant effect on technical efficiency, but having links to the public extension officers and
attending technology and information dissemination events organized through the officers
had a positive effect on technical efficiency for improved varieties of maize. This shows that
efficiency-enhancing production information for the largely commercialized seed
technologies may be much more technical, hence requiring more specialized dissemination.
The findings raise a number of implications for policy and future research. First,
social networks matter for the spread and efficient utilization of new agricultural
technologies. Hence, technology dissemination programs should try to make use of such
networks. Second, inter-village networks matter for farmers’ exposure to and technical
efficiency of improved varieties; hence facilitation of information exchange across village
boundaries may improve awareness creation and the spread and productivity of new
technologies. Third, the power of farmer networks with community leaders and village
administrators can be exploited for increased awareness of improved technologies. Fourth,
extension officers facilitate discussions about crop farming, and help in increasing awareness
and technical efficiency of improved technologies. Therefore, new extension models could be
developed that explicitly build on the synergies between formal and informal information
channels. | en_US |
