LABOR, LIQUIDITY, LEARNING, CONFORMITY AND SMALLHOLDER TECHNOLOGY ADOPTION: THE CASE OF SRI IN MADAGASCAR

Although rice accounts for approximately forty-four percent of land under cultivation and forty-six percent of caloric intake in Madagascar, most farmers cannot produce enough rice to feed their families. Total rice production increased little in the country during the 1990s, and yields were stagnant and well below world average yields. Because of the importance of rice for both family income and nutrition and because of the significant role upland rice cultivation plays in deforestation in Madagascar, intensification of lowland rice production has been a major focus of many development interventions. The System of Rice Intensification (SRI) is a method that has been promoted and closely followed in Madagascar for more than ten years. SRI is remarkable for its dramatic increases in yields achieved without external inputs. While the method is more labor intensive, the doubling or even tripling of yields would appear to make the method extremely profitable. Despite its apparent potential and intensive extension efforts in some areas, adoption rates have generally been low, and the average rate of disadoption (the percentage of households who have tried the method and who no longer practice it) for study area was 40 percent. Using survey data from five communities in Madagascar, a sample selection model and a probit model were used to study three related choices farmers must make concerning the SRI. The first is whether to try the method, and then, conditional on having tried the method a farmer must decide how much of his lowland rice area to put in the SRI. Finally, for all subsequent years, a farmer must decide whether to continue using the method. While many adoption studies have looked at the role of liquidity and labor, few have done so in a dynamic setting. We take advantage of reliable recall data and NGO records on technology use to construct a panel data set, which was used to analyze the effects of learning, labor, liquidity, and social benefits over a five-year period. Learning has been the focus of several recent adoption studies, but this study tries to separate the learning effects from the effects of compliance with authority figures and with social and cultural norms. The results show that planting-season labor and liquidity constraints are extremely important factors in the adoption decisions of Malagasy farmers. Although the method is low-external input, the poorest farmers are not able to take advantage of the technology. This result is very important for development policy-makers in Madagascar who have often seen rice intensification as the most important means by which to alleviate rural poverty in Madagascar.Farm Management,

Better Technology, Better Plots or Better Farmers? Identifying Changes in Productivity and Risk Among Malagasy Rice Farmers

In assessing the productivity gains of a new technology, it is often difficult to determine the extent to which observed output gains are due to the technology itself, rather than to the skill of the farmer or the quality of the plot on which the new technology is tried. This problem of attribution is especially important when technologies are not embodied in purchased inputs such as seed or machinery but result instead from changed farmer cultivation practices. Using data based on observations of farmers in Madagascar who simultaneously practice both a newly introduced and traditional rice production methods, we introduce a method for properly attributing observed productivity and risk changes among new production methods, farmers and plots by controlling for farmer and plot heterogeneity using differential production and yield risk functions. Our results help resolve several outstanding puzzling associated with observed low and incomplete uptake and high rates of disadoption of the new system of rice intensification (SRI) in spite of consistent, sharp yield increases on small farmers' fields without application of additional external inputs.Productivity Analysis,

Missed opportunities and missing markets: Spatio-temporal arbitrage of rice in Madagascar

This paper uses an exceptionally rich data set to test the extent to which markets in Madagascar are integrated across space, time, and form (in converting from paddy to rice) and to explain some of the factors that limit arbitrage and price equalization within a single country. In particular, we use rice price data across four quarters of 2000-2001 along with data on transportation costs and infrastructure availability for nearly 1400 communes in Madagascar to examine the extent of market integration at three different spatial scales sub-regional, regional, and national and determine whether non-integration is due to high transfer costs or lack of competition. The results indicate that markets are fairly well integrated at the sub-regional level and that factors such as high crime, remoteness, and lack of information are among the factors limiting competition. A lack of competition persists at the regional level and high transfer costs impede spatial market integration at the national level. Only six percent of rural communes appear to be intertemporally integrated and there appear to be significant untapped opportunities for interseasonal arbitrage. Income is directly and strongly related to the probability of a commune being in interseasonal competitive equilibrium.Marketing,

Spin chain from membrane and the Neumann-Rosochatius integrable system

We find membrane configurations in AdS_4 x S^7, which correspond to the continuous limit of the SU(2) integrable spin chain, considered as a limit of the SU(3) spin chain, arising in N=4 SYM in four dimensions, dual to strings in AdS_5 x S^5. We also discuss the relationship with the Neumann-Rosochatius integrable system at the level of Lagrangians, comparing the string and membrane cases.Comment: LaTeX, 16 pages, no figures; v2: 17 pages, title changed, explanations and references added; v3: more explanations added; v4: typos fixed, to appear in Phys. Rev.

A Deep Neural Network as Surrogate Model for Forward Simulation of Borehole Resistivity Measurements

Inverse problems appear in multiple industrial applications. Solving such inverse problems require the repeated solution of the forward problem. This is the most time-consuming stage when employing inversion techniques, and it constitutes a severe limitation when the inversion needs to be performed in real-time. In here, we focus on the real-time inversion of resistivity measurements for geosteering. We investigate the use of a deep neural network (DNN) to approximate the forward function arising from Maxwell's equations, which govern the electromagnetic wave propagation through a media. By doing so, the evaluation of the forward problems is performed offline, allowing for the online real-time evaluation (inversion) of the DNN

Hyperbolic outer billiards : a first example

We present the first example of a hyperbolic outer billiard. More precisely we construct a one parameter family of examples which in some sense correspond to the Bunimovich billiards.Comment: 11 pages, 8 figures, to appear in Nonlinearit

Ionization signals from electrons and alpha-particles in mixtures of liquid Argon and Nitrogen - perspectives on protons for Gamma Resonant Nuclear Absorption applications

In this paper we report on a detailed study of ionization signals produced by Compton electrons and alpha-particles in a Time Projection Chamber (TPC) flled with different mixtures of liquid Argon and Nitrogen. The measurements were carried out with Nitrogen concentrations up to 15% and a drift electric feld in the range 0-50 kV/cm. A prediction for proton ionization signals is made by means of interpolation. This study has been conducted in view of the possible use of liquid Ar-N2 TPCs for the detection of gamma-rays in the resonant band of the Nitrogen absorption spectrum, a promising technology for security and medical applications

30 kV coaxial vacuum-tight feedthrough for operation at cryogenic temperatures

In this paper we describe the technology of building a vacuum-tight high voltage feedthrough which is able to operate at voltages up to 30 kV. The feedthrough has a coaxial structure with a grounded sheath which makes it capable to lead high voltage potentials into cryogenic liquids, without risk of surface discharges in the gas phase above the liquid level. The feedthrough is designed to be used in ionization detectors, based on liquefied noble gases, such as Argon or Xenon