Altruism, Cooperation, and Efficiency: Agricultural Production in Polygynous Households

Altruism among family members can, in some cases, inhibit cooperation by increasing the utility that players expect to receive in a non-cooperative equilibrium. To test this, we examine agricultural productivity in polygynous households in West Africa. We find that cooperation is greater – production is more efficient – among co-wives than among husbands and wives because co-wives are less altruistic towards each other. The results are not driven by scale effects or self-selection into polygyny. Nor can they be explained by greater propensity for cooperation among women generally or by the household head acting as an enforcement mechanism for others' cooperative agreements.altruism, non-cooperative behavior, household bargaining, polygyny, Africa

Impact of Conditional Cash Transfers and Remittances on Credit Market Outcomes in Rural Nicaragua

The impact of public and private transfers on credit markets has not been sufficiently studied and understanding any spill over effects caused by these transfers may be useful for policy makers. This paper estimates the impact of Conditional Cash Transfers (CCTs) and remittances received by poor households in rural Nicaragua on their decision to request a loan. We find that, on average, CCTs did not affect the request of credit while remittances increased it, controlling for potential endogeneity. We argue the reduction in income risk provided by remittances changes borrowers’ expected marginal returns to a loan and/or their creditworthiness, as perceived by lenders. The successful enforcement of the use of CCTs on long-term investments seems to have avoided externalities on the use of short-term credit these households have access to and their creditworthiness.International Development, D14, F22, O15,

Altruism, cooperation, and efficiency: Agricultural production in polygynous households

Altruism among family members can, in some cases, inhibit cooperation by increasing the utility that players expect to receive in a non-cooperative equilibrium. To test this, we examine agricultural productivity in polygynous households in West Africa. We find that cooperation is greater - production is more efficient - among co-wives than among husbands and wives because co-wives are less altruistic towards each other. The results are not driven by scale effects or self-selection into polygyny. Nor can they be explained by greater propensity for cooperation among women generally or by the household head acting as an enforcement mechanism for others' cooperative agreements

Nonlinear Dirac operator and quaternionic analysis

Properties of the Cauchy-Riemann-Fueter equation for maps between quaternionic manifolds are studied. Spaces of solutions in case of maps from a K3-surface to the cotangent bundle of a complex projective space are computed. A relationship between harmonic spinors of a generalized nonlinear Dirac operator and solutions of the Cauchy-Riemann-Fueter equation are established.Comment: Cosmetic changes onl

Exploring the potential climate change impact on urban growth in London by a cellular automata-based Markov chain model

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.Urbanization has become a global trend under the combined influence of population growth, socioeconomic development, and globalization. Even though recent urban planning in London has been more deliberate, the relationships between climate change and urban growth in the context of economic geography are still somewhat unclear. This study relies on rainfall prediction with the aid of the Statistical DownScaling Model (SDSM), which provides the statistical foundation for future flooding potential within the urban space of London while considering major socioeconomic policies related to land use management. These SDSM findings, along with current land use policies, were included as other factors or constraints in a cellular automata-based Markov Chain model to simulate and predict land use changes in London for 2030 and 2050. Two scenarios with the inclusion and exclusion of flood impact factor, respectively, were applied to evaluate the impact of climate change on urban growth. Findings indicated: (1) mean monthly projected precipitation derived by SDSM is expected to increase for the year 2030 in London, which will affect the flooding potential and hence the area of open space; (2) urban and open space are expected to increase > 16 and 20km 2 (in percentage of 1.51 and 1.92 compared to 2012) in 2030 and 2050, respectively, while agriculture is expected to decrease significantly due to urbanization and climate change; (3) the inclusion of potential flood impact induced from the future precipitation variability drives the development toward more open space and less urban area.The research is supported by the Global Innovation Initiative (British Council Grant No. Gll206), funded by the British Council and the Department for Business, Innovation and Skills

The weak localization for the alloy-type Anderson model on a cubic lattice

We consider alloy type random Schr\"odinger operators on a cubic lattice whose randomness is generated by the sign-indefinite single-site potential. We derive Anderson localization for this class of models in the Lifshitz tails regime, i.e. when the coupling parameter $\lambda$ is small, for the energies $E \le -C \lambda^2$.Comment: 45 pages, 2 figures. To appear in J. Stat. Phy

Computing Equilibria of Prediction Markets via Persuasion

We study the computation of equilibria in prediction markets in perhaps the most fundamental special case with two players and three trading opportunities. To do so, we show equivalence of prediction market equilibria with those of a simpler signaling game with commitment introduced by Kong and Schoenebeck (2018). We then extend their results by giving computationally efficient algorithms for additional parameter regimes. Our approach leverages a new connection between prediction markets and Bayesian persuasion, which also reveals interesting conceptual insights

Seasonal prediction of bottom temperature on the Northeast U.S. Continental Shelf

© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Chen, Z., Kwon, Y.-O., Chen, K., Fratantoni, P., Gawarkiewicz, G., Joyce, T. M., Miller, T. J., Nye, J. A., Saba, V. S., & Stock, B. C. Seasonal prediction of bottom temperature on the Northeast U.S. Continental Shelf. Journal of Geophysical Research: Oceans, 126(5), (2021): e2021JC017187, https://doi.org/10.1029/2021JC017187.The Northeast U.S. shelf (NES) is an oceanographically dynamic marine ecosystem and supports some of the most valuable demersal fisheries in the world. A reliable prediction of NES environmental variables, particularly ocean bottom temperature, could lead to a significant improvement in demersal fisheries management. However, the current generation of climate model-based seasonal-to-interannual predictions exhibits limited prediction skill in this continental shelf environment. Here, we have developed a hierarchy of statistical seasonal predictions for NES bottom temperatures using an eddy-resolving ocean reanalysis data set. A simple, damped local persistence prediction model produces significant skill for lead times up to ∼5 months in the Mid-Atlantic Bight and up to ∼10 months in the Gulf of Maine, although the prediction skill varies notably by season. Considering temperature from a nearby or upstream (i.e., more poleward) region as an additional predictor generally improves prediction skill, presumably as a result of advective processes. Large-scale atmospheric and oceanic indices, such as Gulf Stream path indices (GSIs) and the North Atlantic Oscillation Index, are also tested as predictors for NES bottom temperatures. Only the GSI constructed from temperature observed at 200 m depth significantly improves the prediction skill relative to local persistence. However, the prediction skill from this GSI is not larger than that gained using models incorporating nearby or upstream shelf/slope temperatures. Based on these results, a simplified statistical model has been developed, which can be tailored to fisheries management for the NES.This work was supported by NOAA's Climate Program Office's Modeling, Analysis, Predictions, and Projections (MAPP) Program (NA17OAR4310111, NA19OAR4320074), and Climate Program Office's Climate Variability and Predictability (CVP) Program (NA20OAR4310482). We acknowledge our participation in MAPP's Marine Prediction Task Force

1/4-BPS M-theory bubbles with SO(3) x SO(4) symmetry

In this paper we generalize the work of Lin, Lunin and Maldacena on the classification of 1/2-BPS M-theory solutions to a specific class of 1/4-BPS configurations. We are interested in the solutions of 11 dimensional supergravity with $SO(3)\times SO(4)$ symmetry, and it is shown that such solutions are constructed over a one-parameter familiy of 4 dimensional almost Calabi-Yau spaces. Through analytic continuations we can obtain M-theory solutions having $AdS_2\times S^3$ or $AdS_3\times S^2$ factors. It is shown that our result is equivalent to the $AdS$ solutions which have been recently reported as the near-horizon geometry of M2 or M5-branes wrapped on 2 or 4-cycles in Calabi-Yau threefolds. We also discuss the hierarchy of M-theory bubbles with different number of supersymmetries.Comment: 22 pages, JHEP3.cls; v2. revised version. showed that our results agree with previous works hep-th/0605146 and hep-th/061219