Parametric and Non-Parametric Estimation of Soil Conservation Impact on Productivity in the Northwestern Ethiopian Highlands

The impact of fanya juu bunds on productivity in a high rainfall area in the Ethiopian highlands is analyzed based on data from a cross section household survey with multiple plot observations per household. The results from parametric and non-parametric analysis indicated that productivity from conserved plots was lower than from non-conserved plots. The Oaxaca-Blinder productivity decomposition results showed that there was little difference in plot characteristics between conserved and non-conserved plots, however the returns to those characteristics were higher for non-conserved plots. The sensitivity analysis, increasing fodder grass production on bunds, suggests that there are possibilities to make conserved plots as productive as non-conserved ones. The findings imply that fanya juu bunds may be inappropriate to the local conditions under the existing condition. Farmers in the study area reported that these bunds h ave problem of water-logging, reduce land available for production, and create difficulties in turning the ox-drawn plough due to narrow bund sp acing. Apart from these, there is no attempt made to integrate these bunds with soil fertility management techniques. Overall, these results yield important lessons for future design of conservation technologies that have both physical and economic benefits as well as that are best suited to the local conditions.Yield decomposition, soil conservation, switching regression, stochastic dominance analysis, matching methods, Land Economics/Use, Productivity Analysis, C21, C23, Q12, Q15, Q16,

Tenure Insecurity, Transaction Costs in the Land Lease Market and their Implications for Gendered Productivity Differentials

This study sets out to assess 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 landlord's tenure insecurity leads to sub-optimal level of effort on tenant's part, via its impact on the likelihood of contract renewal. The landlord's enforcement ability is also shown to increase the optimal level of effort. The empirical findings support the hypothesis that female heads of households have higher tenant turnover and lower enforcement ability. The results, however, show that contract renewal is not strongly linked to productivity.productivity, female headed households, contract length, enforcement ability, Land Economics/Use, D2, Q12, Q15, C21, C7,

Impact of Land Certification on Land Rental Market Participation in Tigray Region, Northern Ethiopia

There is a renewed interest in whether land reforms can contribute to market development in Africa and whether land reforms can be pro-poor. This paper uses unique household panel data from Tigray region in Ethiopia to assess the impact of the 1998 low-cost land registration and certification reform on land rental market participation over a period of eight years after the reform, using random effects probit and tobit panel data models for land leased out and leased in, while correcting for unobservable heterogeneity and endogeneity of having certificate. The analysis revealed that the land reform contributed to increased land rental market participation. Female-headed households became more willing to rent out land and making land available for more efficient producers. Average areas leased out and leased in increased after certification. The land rental market remained characterised with significant and non-convex transaction costs also after the reform as evidenced by significant state dependence, a low response to own holding size and a high share of non-participation in the land market, leaving room for further improvement.Land certification; land rental market; panel data analysis; unobserved heterogeneity; household response; female-headed households

Measuring the Compactness of Political Districting Plans

The United States Supreme Court has long recognized compactness as an important principle in assessing the constitutionality of political districting plans. We propose a measure of compactness based on the distance between voters within the same district relative to the minimum distance achievable -- which we coin the relative proximity index. We prove that any compactness measure which satisfies three desirable properties (anonymity of voters, efficient clustering, and invariance to scale, population density, and number of districts) ranks districting plans identically to our index. We then calculate the relative proximity index for the 106th Congress, requiring us to solve for each state's maximal compactness; an NP-hard problem. Using two properties of maximally compact districts, we prove they are power diagrams and develop an algorithm based on these insights. The correlation between our index and the commonly-used measures of dispersion and perimeter is -.22 and -.06, respectively. We conclude by estimating seat-vote curves under maximally compact districts for several large states. The fraction of additional seats a party obtains when their average vote increases is significantly greater under maximally compact districting plans, relative to the existing plans.

The Double Slit Experiment With Polarizers

The double slit experiment provides a standard way of demonstrating how quantum mechanics works. We consider modifying the standard arrangement so that a photon beam incident upon the double slit encounters a polarizer in front of either one or both of the slits.Comment: 6 page

Multitasking, Learning, and Incentives: A Cautionary Tale

We develop a multi-period, multi-task principal-agent model in which neither the principal nor the agent knows the mapping from actions to outputs. The agent can learn about the production function over time by exerting effort and observing output. The model has a stark prediction: incentives may have a negative impact on agent effort if, by exerting effort, they learn their ability is lower than their prior beliefs. To provide evidence on the model’s predictions, we conduct a field experiment in fifty Houston public schools, where students, parents, and teachers were rewarded with financial incentives. The experimental data is consistent with the model’s most distinguishing predictions, though other explanations are possible.