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We report results from a randomized field experiment conducted in the Tigray region of Ethiopia, which tests the impact of interaction with migrants on host community members’ attitudes towards migrants. In three treatment groups, host community members were randomly paired with a migrant from a nearby refugee camp to play an incentivized guessing game. In the first of these treatments, the game was neutral in content, in the second it introduced subtle cues to economic matters, and in the third subtle cues to ethnic identity. In a fourth treatment, host community members were paired with other host community members to play the neutral game, and in the control condition host community members did not interact with anyone. The results show that, compared to the control group, interaction with a migrant significantly improved attitudes towards them. Subtle cues to economic matters or identity did not diminish this effect. However, we see similar effects on attitudes to migrants in the treatment group where hosts interacted with other hosts, which suggests that the effects are driven by human interaction in general, rather than by interacting specifically with a migrant. The effects of interaction are not much affected by the characteristics of the paired hosts and migrants, though host respondents in low skill occupations appear to respond more favourably to the treatments. Interestingly, however, we find no effects of the treatments on how migrants believe they are perceived by host community members.

In this article, we study the impact of an institutional intervention on market efficiency in Ethiopia. More specifically, we study whether regional warehouses that are connected to a national commodity exchange reduce transaction cost and price dispersion between regions. In order to identify the causal effect we take advantage of the fact that the warehouses that are connected to the Ethiopian Commodity Exchange were sequentially rolled out. Using retail price data and information about warehouse operation from 2007-2012, we find that the average price spread between market pairs is reduced by 0.86-1.775 ETB when both markets have an operating warehouse. This is a substantial reduction considering that the average price spread over the full period is 3.33 ETB.

Weather fluctuations tend to be as important as climate change in farmers’ decision making in countries such as Ethiopia that have virtually no weather insurance. This paper assesses the distinct impacts of weather and climate change measures on agricultural productivity of households, measured in terms of crop revenue, in the Amhara region of Ethiopia. Four waves of survey data, which included about 1500 households in each round, combined with interpolated daily temperature and monthly rainfall data from the meteorological stations, are employed in the analysis. The distinction between weather and climate is highlighted by observations in the temperature data, which show that the pattern of temperature for both short-term and long-term values follows a bell-shaped distribution, with the striking feature that the extreme ends of the distribution have fatter tails for the long term values. The analysis employs monthly rainfall and 14 temperature categories related to weather measures and four categories corresponding with the extreme ends of the long-term temperature distribution. The analysis also distinguishes between summer and spring seasons and different crops, in recognition that Ethiopia’s agriculture is multi-cropping and multi-season. The major findings show that temperature effects are distinctly non-linear, but only when the weather measures are combined with the extreme ends of the distribution of the climate measures. In addition, rainfall generally has a less important role to play than temperature, contrary to expectations for rainfed agriculture.

Land tenure arrangements in Africa are generally skewed in favour of males. Compared to males, female plot owners face complex sets of constraints and systemic high tenure insecurity which culminate in low yields. In order to obtain better returns, some females rent their plots to males, but risk losing the plots to their tenants. A model has been constructed to explain rentingout decisions of female small landholders, an issue largely ignored in the agricultural economics literature. The results, based on a survey of female landholders in Ethiopia, highlight the factors that explain renting-out decisions.

The paper assesses the potential for rent generation, distinguishing between resource and intra-marginal rent, in the North Sea herring fishery. A bioeconomic model combining fish population dynamics with the economic structure of the fishery is used to generate equations to compute the different rents. A combination of biological data with vessel-level economic data for UK pelagic trawlers is employed in estimations. In order to assess the dynamics of both resource and intra-marginal rent generation, the model is evaluated under various assumptions with regard to price, cost, and discount rate. Potential total rents are measured at £90-91 million annually of which resource rent makes up about £89.0 million with intra-marginal rent measured in the order of only £2.0 million. This compares to an actual rent in 2007 estimated at £ 16.3 million. The results show that, in this fishery, rent is dissipated almost entirely due to excess effort while very little is dissipated due to suboptimal stock size.

We examine Trevon Logan's 2009 claim to have found low levels of nutrition among British worker's households in the late 19th century. Using the same data, we conclude that Logan's estimates are thirty percent too low. Logan buttressed his estimates by claiming that the income elasticity of calories demand was unusually high among these households, relative to other estimates, reflecting great hunger. We find that the elasticity is high, but not outside the range observed in other data sets. We also warn against the simple assertion that a high elasticity implies hunger.

This paper analyses the impact of a low cost and restricted rights land certification program on the productivity of female-headed households. The analysis is based on plot level panel data from the East Gojjam and South Wollo Zones in the Amhara region of Ethiopia. The results suggest a positive and significant effect of certification on plot-level productivity, particularly on plots rented out to other operators. In addition, the results show that certification has different impacts on male and female productivity with female-headed households gaining significantly more and with zonal differences in the effectiveness of certification impacts.

The importance of providing secure land rights to smallholder farmers in developing countries is now widely recognized. In line with this, our paper analyzes the impact of land certification on boosting productivity of female-headed households in Ethiopia, which are believed to be systematically more tenure insecure than their male counterparts. Based on parametric and semi-parametric analyses, the impact of certification on plot-level productivity is positive and significant. However, certification has different impacts on male and female productivity: male-headed households gain significantly and women gain only modestly. Hence, the results indicate that, while certification is clearly beneficial to farm-level productivity, it does not necessarily lead to more gains for female-headed households.

Devoting time to off-farm activities, while complementing agricultural incomes, may be constrained by labor availability and financial capacity. This paper assesses the importance of rainfall patterns, which condition the availability of agricultural labor, and financial constraints on off-farm employment decisions. Using panel data from Ethiopia, which include experimental rate-of-time preference measures, we found that these and rainfall are significant determinants off-farm employment. Rural development policies should take into account the financial capacity of households and the role of off-farm opportunities as safety nets in the face of weather uncertainty.

This article assesses the relative importance of risk preferences and rainfall availability on households’ decision to engage in off-farm employment. Devoting time for off-farm activities, while it helps households earn additional incomes, involves a number of uncertainties. Unique panel data from Ethiopia which includes experimentally generated risk preference measures combined with longitudinal rainfall data is used in the analysis. An off farm participation decision and activity choice showed that both variability and reduced availability of rainfall as well as neutral risk preferences increase the likelihood of off-farm participation. From policy perspective, the results imply that expanding off farm opportunities could act as safety nets in the face of weather uncertainty. In addition, policy initiatives geared towards encouraging income diversification through off farm employment need to address underlying factor that condition risk bearing ability of households.

In an attempt to address a racially skewed land distribution and alleviate rural poverty, Zimbabwe has, since its independence, pursued redistributive land reform programmes. The latest phase of these programmes is the Fast Track Land Reform Programme (FTLRP) launched in 2000 to accelerate compulsory acquisition and resettlement of land. This paper uses data on FTLRP beneficiaries and a control group of unsuccessful communal applicants to examine the programme’s impact on the technical efficiency of its beneficiaries. To account for possible systematic selection into FTLRP, we employ a probit selection equation and estimate a corrected Cobb- Douglas stochastic frontier function model. The resultant inefficiency model estimates reveal that FTLRP beneficiaries are more technically efficient than communal farmers. Further, there exist a nonlinear relationship between farm size and technical efficiency. Fencing parcels and livestock holdings is found to improve technical efficiency suggesting that alleviating resource constraints would enhance technical efficiency of smallholder agriculture.

In this paper we use farmers' actual experiences with changes in rainfall levels and their responses to these changes to assess if patterns of fertilizer use are responsive to changes in rainfall patterns. Using plot and farm level panel data from the central Highlands of Ethiopia matched with corresponding village level rainfall data; results show that both the current year’s decision to adopt and the intensity of fertilizer adoption is positively associated with higher rainfall levels experienced in the previous year. Furthermore, we find a concave relationship between previous season rainfall levels and fertilizer adoption, indicating that too much rainfall discourages adoption. Abundant rainfall in the previous year could depict relaxed liquidity constraints and increased affordability of fertilizer, which makes rainfall availability critical in severely credit constrained environments. In light of similar existing literature, the major contribution of the study is its use of plot level panel data, which permits us to investigate the importance of plot characteristics in fertilizer adoption decisions.

In this paper we use farmers' actual experiences with changes in rainfall levels and their responses to these changes to assess if patterns of fertilizer use are responsive to changes in rainfall patterns. Using plot and farm level panel data from the central Highlands of Ethiopia matched with corresponding village level rainfall data; results show that both the current year’s decision to adopt and the intensity of fertilizer adoption is positively associated with higher rainfall levels experienced in the previous year. Furthermore, we find a concave relationship between previous season rainfall levels and fertilizer adoption, indicating that too much rainfall discourages adoption. Abundant rainfall in the previous year could depict relaxed liquidity constraints and increased affordability of fertilizer, which makes rainfall availability critical in severely credit constrained environments. In light of similar existing literature, the major contribution of the study is its use of plot level panel data, which permits us to investigate the importance of plot characteristics in fertilizer adoption decisions.

This paper seeks to find explanations to why land productivity is lower on land rented out by female landlord households than on land rented out by male landlord households. First it is demonstrated that this productivity differential is highly significant after controlling for land productivity using nearest neighbour and kernel plot matching methods. Then we test alternative hypotheses that possibly may explain the productivity differential. These include transaction costs in the land rental market, larger problem with Marshallian inefficiency on land rented out by female landlords, poorer ability to screen good tenants and evict bad tenant by female landlords, and larger proportion of pure landlords (with poorer monitoring capacity) among female landlords. Using GLS and controlling for sample selection we found evidence of Marshallian inefficiency in the analysis but this could not explain the gender productivity differential. Female landlords have tenants who are older, own less oxen, are more related, and under longer-term contracts. In the parametric regressions land productivity was significantly lower on plots rented out to in-law tenants and this appeared to explain the gender productivity differential. Female landlords may be forced to rent their land to their inlaws and they are unable to evict them even if they are inefficient land users. Land reforms that strengthen women’s land rights may therefore be good for efficiency as well as equity. Recent land regulations restricting renting out of land to maximum half of the farm area may contribute to weaken women’s land rights as a large share of the poor female landlords currently rent out more than half of their land because they lack the necessary nonland resources to farm efficiently.

This thesis consists of four papers. The titles and abstracts of the various essays are as follows. Paper 1: Tenure Insecurity, Transaction Costs in the Land Lease Market and Implications for Gendered Productivity Differentials This study assesses the link between land leasing behavior and productivity differentials between male and female-headed households. A double-moral hazard model allows us to show that the landlord’s tenure insecurity leads to a sub-optimal level of effort on the tenant’s part, via its impact on the likelihood of contract renewal. The model also predicts that a high search cost of a landlord leads to a higher probability of contract renewal. A lower probability of contract renewal leads to lower levels of tenant’s effort, and vice versa. The empirical findings support the hypotheses that female household heads have lower enforcement ability and that tenure insecurity is a significant negative determinant of productivity. However, the results show no support for a lower likelihood of contract renewal by female-headed households or for a significant impact of contract renewal on productivity. Paper 2: Heterogeneous Risk Preferences, Transaction Costs and Land Contract Choice The paper analyzes how heterogeneities in risk preferences, rate of time preferences and transaction costs affect the choice of contracts among participants in the land lease market. The analysis draws from both agency and transaction cost theories, which propose alternative explanations of contract choice. Unique data from Ethiopia, containing experimental risk, rate of time preference measures and transaction costs are employed in the analysis. Tenant characteristics are more important than those of landlords in explaining contract choice. The results do not support the risk-sharing hypothesis of the agency theory as a motivation for contract choice while there is some support that discount rates and transaction costs affect contract choice. The results also viii indicate that the land lease market serves as a resource pooling mechanism by bringing poorer landlords and tenants into sharing arrangements. Paper 3: Biodiversity Conservation Under an Imperfect Seed System: The role of Community Seed Banking Scheme The study is an empirical investigation of agrobiodiversity conservation decisions of small farmers in the central highlands of Ethiopia. The primary objective is to measure the effectiveness of Community Seed Banking (CSB) in enhancing diversity while providing productivity incentives. Our results indicate a significant impact of participation in CSB on farm-level agrobiodiversity. However, the level biodiversity conservation was not found to have the expected reinforcing impact on participation indicating no support for simultaneity. CSB participation also led to increase in productivity consistent with the need for such incentives to enhance diversity at a farm level. Our assessment of the performance of the GLS estimator yielded a significant discrepancy between the GLS and bootstrap estimates. This led to the conclusion that bootstrapping asymptotic estimations might be required for appropriate inference. Paper 4: Environmental Change, Species’ Coping Ability and the Insurance Value of Biodiversity This paper develops a measure of the value of biodiversity by incorporating a stochastic change in the environmental factor into an economy-ecosystem model of biodiversity. The analysis draws from an ecological model specifying the relationship between aggregate productivity, responsiveness to environmental change, and diversity. The value of biodiversity is derived as the contribution of diversity in enhancing the ecosystem’s adaptive response to environmental change. The results are relevant to biodiversity conservation efforts that target areas with differing degrees of environmental variation. In addition, our analysis of some features of global warming the results imply that with increased concerns of global warming, more needs to be invested in biodiversity.

This paper develops a real options approach to the optimal sequencing of antiretroviral drug cocktails for HIV/AIDS patients in resource-poor settings. The analysis focuses on the implications of endogenous resistance mutations in the virus that reduce or eliminate the effectiveness of individual drugs within a cocktail when lack of laboratory equipment prevents these from being identified. Using a model with two drug cocktails, we show that the first-line therapy should be introduced later than in the case without resistance mutations and that the second-line therapy should be introduced earlier. We go on to discuss implications for comparative cost-effectiveness analyses.