Idiosyncratic shocks, risk management and welfare dynamics in rural Ghana

International Development, Risk and Uncertainty,

GCD sums and sum-product estimates

In this note we prove a new estimate on so-called GCD sums (also called G\'{a}l sums), which, for certain coefficients, improves significantly over the general bound due to de la Bret\`{e}che and Tenenbaum. We use our estimate to prove new results on the equidistribution of sequences modulo 1, improving over a result of Aistleitner, Larcher, and Lewko on how the metric poissonian property relates to the notion of additive energy. In particular, we show that arbitrary subsets of the squares are metric poissonian.I did this paper between the end of my DPhil in Oxford and the beginning of the Junior Research Fellowship in Cambridge

Smallholder Participation in Agricultural Value Chains: Comparative Evidence from Three Continents

Supermarkets, specialized wholesalers, and processors and agro-exporters’ agricultural value chains have begun to transform the marketing channels into which smallholder farmers sell produce in low-income economies. We develop a conceptual framework through which to study contracting between smallholders and a commodity-processing firm. We then conduct an empirical meta-analysis of agricultural value chains in five countries across three continents (Ghana, India, Madagascar, Mozambique, and Nicaragua). We document patterns of participation, the welfare gains associated with participation, reasons for non-participation, the significant extent of contract non-compliance, and the considerable dynamism of these value chains, as farmers and firms enter and exit frequently.

Smallholder Participation in Agricultural Value Chains: Comparative Evidence from Three Continents

Supermarkets, specialized wholesalers, and processors and agro-exporters’ agricultural value chains have begun to transform the marketing channels into which smallholder farmers sell produce in low-income economies. We develop a conceptual framework through which to study contracting between smallholders and a commodity-processing firm. We then conduct an empirical meta-analysis of agricultural value chains in five countries across three continents (Ghana, India, Madagascar, Mozambique, and Nicaragua). We document patterns of participation, the welfare gains associated with participation, reasons for non-participation, the significant extent of contract non-compliance, and the considerable dynamism of these value chains, as farmers and firms enter and exit frequently.Agricultural Value Chains, Contract Farming, Africa, Asia, Latin America

Household Shocks and Education Investment in Madagascar

This paper measured the extent to which households in Madagascar adjust children's school attendance in order to cope with exogenous shocks to household income, assets and labour supply. Our analysis was based on a unique data set with 10 years of recall data on school attendance and household shocks. We found that the probability of a child dropping out of school increased significantly when the household experienced an illness, death or asset shock. We proposed a test to distinguish whether the impact of shocks on school attendance could be attributed to credit constraints, labour market rigidities, or a combination of the two. The results of the test suggested that credit constraints, rather than labour market rigidities, explain the inability of households in Madagascar to keep their children in school during times of economic distress

Scaling law for the electromagnetic form factors of the proton

The violation of the scaling law for the electric and magnetic form factors of the proton are examined within the cloudy bag model. The suppression of the ratio of the electric and magnetic form factors is natural in the bag model. The pion cloud plays a moderate role in understanding the recent data from TJNAF.Comment: 8 pages, REVTeX, 2 figures include

Impact of Corn Silage Moisture and/or Kernel Processing at Harvest on Finishing Steer Growth Performance, Efficiency of Dietary Net Energy Utilization and Carcass Traits

Study Description: Red Angus steers (n = 192; initial shrunk BW = 983 ± 62.3 lbs) were used in the 112 d finishing experiment at the Southeast Research Farm (SERF) of the South Dakota Agricultural Experiment Station in Beresford. Steers were from a single source and obtained from a local SD auction facility. Steers were received 2 weeks prior to trial initiation. Steers were offered a common diet containing 60% concentrate upon arrival. Steers were transitioned to a 90% concentrate diet over the course of 14 d. Steers were consuming the finishing diet (Table 1) at the initiation of the experiment. Fresh feed was manufactured once daily for each treatment in a single batch using a stationary mixer and bunks were managed for ad libitum access to feed. Actual diet formulation and composition is based upon weekly DM analyses, tabular nutrient values, and corresponding feed batching records. Diets presented in Table 1 are actual DM diet composition, tabular nutrient concentrations, and tabular energy values (Preston, 2016)

MOST photometry of the RRd Lyrae variable AQ Leo: Two radial modes, 32 combination frequencies, and beyond

Highly precise and nearly uninterrupted optical photometry of the RR Lyrae star AQ Leo was obtained with the MOST (Microvariability & Oscillations of STars) satellite over 34.4 days in February-March 2005. AQ Leo was the first known double-mode RR Lyrae pulsator (RRd star). Three decades after its discovery, MOST observations have revealed that AQ Leo oscillates with at least 42 frequencies, of which 32 are linear combinations (up to the sixth order) of the radial fundamental mode and its first overtone. Evidence for period changes of these modes is found in the data. The other intrinsic frequencies may represent an additional nonradial pulsation mode and its harmonics (plus linear combinations) which warrant theoretical modeling. The unprecedented number of frequencies detected with amplitudes down to millimag precision also presents an opportunity to test nonlinear theories of mode growth and saturation in RR Lyrae pulsators.Comment: accepted for publication in MNRAS; revision v2 : broken references have been fixe