142 research outputs found
Spatial price transmission and market integration in Senegal’s groundnut market
The groundnut sector is the largest of Senegal’s agricultural sectors. It has been subject to various degrees of intervention since the country’s independence. Some, including the determination of farm prices by the government have survived the wave of reforms of the 1980s. Groundnut pricing policies have been the source of major transfers from farmers to the groundnut milling industry, which until 2007, was dominated by SONACOS, a publicly owned parastatal. The state was thus a major beneficiary of the transfers. In 2007, the company was privatized and is now privately owned, raising even greater concerns about the distribution of implications of pricing policies for groundnuts. The paper examines the potential ramifications of liberalizing groundnut prices in terms of its impact on prices received by producers and paid by the milling industry. One fundamental question in the analysis is the extent to which local markets would respond to such a move. To answer this question, the paper presents a dynamic model of price formation that uses estimates of spatial integration across local markets to measure the response of local agricultural prices to policy changes. We then apply this model to simulate the impact of liberalizing groundnut prices to allow domestic prices to reflect their international levels. We find that doing so would change prices in the border city of Dakar, which happens to be the central market that determines prices in the local markets of the producing regions of Kaolack and Fatick. We also find that if markets had been fully liberalized when SONACOS was privatized in January 2007, then groundnut prices would have been higher and that the increase in prices would have been passed on almost entirely to producers in Kaolack and, to a lesser extent, to producers in Fatick. Such reforms would have reversed the longstanding discrimination of groundnut farmers. Prices received by farmers in Kaolack over a period of one year would have increased from 352 FCFA/kg to 494 FCFA/kg of shelled groundnuts. For farmers in the Fatick region, prices would increase from 389 FCFA/kg to 474 FCFA/kg.groundnuts, Liberalization, marketing integration, pricing policies, Privatization,
Non-affine response: jammed packings versus spring networks
We compare the elastic response of spring networks whose contact geometry is
derived from real packings of frictionless discs, to networks obtained by
randomly cutting bonds in a highly connected network derived from a
well-compressed packing. We find that the shear response of packing-derived
networks, and both the shear and compression response of randomly cut networks,
are all similar: the elastic moduli vanish linearly near jamming, and
distributions characterizing the local geometry of the response scale with
distance to jamming. Compression of packing-derived networks is exceptional:
the elastic modulus remains constant and the geometrical distributions do not
exhibit simple scaling. We conclude that the compression response of jammed
packings is anomalous, rather than the shear response.Comment: 6 pages, 6 figures, submitted to ep
Long-term care use after a stroke or femoral fracture and the role of family caregivers
Background: There has been a shift from institutional care towards home care, and from formal to informal care to
contain long-term care (LTC) costs in many countries. However, substitution to home care or informal care might
be harder to achieve for some conditions than for others. Therefore, insight is needed in differences in LTC use, and
the role of potential informal care givers, across specific conditions. We analyze differences in LTC use of previously
independent older patients after a fracture of femur and stroke, and in particular examine to what extent having a
partner and children affects LTC use for these conditions.
Methods: Using administrative data on Dutch previously independent older people (55+) with a fracture of femur
or stroke in 2013, we investigate their LTC use in the year after the condition takes place. We use administrative
treatment data to select individuals who were treated by a medical specialist for a stroke or femoral fracture in
2013. Subsequent LTC use is measured as using no formal care, home care, institutional care or being deceased at
13 consecutive four-weekly periods after initial treatment. We relate long-term care use to having a partner, having
children, other personal characteristics and the living environment.
Results: The probability to use no formal care 1 year after the initial treatment is equally high for both conditions,
but patients with a fracture are more likely to use home care, while patients with a stroke are more likely to use
institutional care or have died. Having a spouse has a negative effect on home care and institutional care use, but
the timing of the effect, especially for institutional care, differs strongly between the two conditions. Having
children also has a negative effect on formal care use, and this effect is consistently larger for patients with a
fracture than patients with a stroke.
Conclusion: As the condition and the effect of potential informal care givers matter for subsequent long-term care
use, policy makers should take the expected prevalence of specific conditions within the older people population
into account when designing long-term car
The microeconomics of adaptation: Evidence from smallholders in Ethiopia and Niger
Climate change is expected to bring higher temperatures, changes to rainfall patterns and in many places increased frequency and severity of extreme weather. Climate change is slated to affect the global food equation both on the supply and demand side as well as local level food systems where small farm communities often depend on local and their own production. As climate change has become more pronounced, the risk to land-based food security faced by many of the world's poor, such as rural communities in Ethiopia and Niger, seems to have become more intense and less predictable. To avoid food insecurity in response to climatic and other stressors, adaptation by small-scale, subsistence farms needs to be accelerated. To effectively intervene to do so, there is a need to understand adaptive behavior in terms of its drivers and its relation with welfare outcomes such as food security. In this paper, we develop a conceptual framework of risk and adaptation, use regression and cluster analysis and the most recent version of the Living Standards Measurement Surveys data for rural areas in Ethiopia and Niger, to advance our understanding. We find that adaptation is associated with lower food insecurity in Ethiopia but not in Niger. Formal education appears as a central element of adaptive capacity and is associated with both adaptive production and income strategies. Female-headed households are much less adapted to a changing climate. Perceived risk based on past hazard experience is crucial for adaptation. Results from the cluster analysis confirm that spatial poverty traps exist. To maintain or enhance welfare in the short term and resilience in the long run in the face of a changing climate, policy makers would do well to focus on micro-regions identified as highly food insecure and build adaptive capacity through, for example, gender inclusive education interventions
Grote verschillen in eigen bijdrage aan ouderenzorg
Wie gebruikmaakt van ouderenzorg betaalt vaak een eigen bijdrage. Zeker in het verpleeghuis kunnen de kosten voor
ouderen daardoor flink oplopen. Vanwege die kosten staan de eigen bijdragen ook voortdurend ter discussie. Tegelijk
is er eigenlijk maar weinig bekend over hoe de eigen bijdragen precies uitpakken voor de financiële situatie van
ouderen. Dit artikel poogt hier verandering in te brengen door met behulp van gedetailleerde administratieve data de
kosten van de eigen bijdragen voor verschillende groepen ouderen in kaart te brengen. De lage inkomensgroepen
blijken, als deel van hun inkomen, het meeste kwijt te zijn: hun behoefte aan zorg is het grootst, en zij gebruiken
relatief veel verpleeghuiszorg, waarvoor de eigen betalingen het hoogst zijn
Importance of exposure dynamics of metal-based nano-ZnO, -Cu and -Pb governing the metabolic potential of soil bacterial communities.
Metal-based engineered nanomaterials (ENMs) are known to affect bacterial processes and metabolic activities. While testing their negative effects on biological components, studies traditionally rely on initial exposure concentrations and thereby do not take into consideration the dynamic behavior of ENMs that ultimately determines exposure and toxicity (e.g. ion release). Moreover, functional responses of soil microbial communities to ENMs exposure can be caused by both the particulate forms and the ionic forms, yet their relative contributions remain poorly understood. Therefore, we investigated the dynamic changes of exposure concentrations of three different types of ENMs (nano-ZnO, -Cu and -Pb) and submicron particles (SMPs) in relation to their impact on the capacity of soil bacterial communities to utilize carbon substrates. The different ENMs were chosen to differ in dissolution potential. The dynamic exposures of ENMs were considered using a time weighted average (TWA) approach. The joint toxicity of the particulate forms and the ionic forms of ENMs was evaluated using a response addition model. Our results showed that the effect concentrations of spherical nano-ZnO, -Cu and SMPs, and Pb-based perovskites expressed as TWA were lower than expressed as initial concentrations. Both particulate forms and ionic forms of spherical 18nm, 43nm nano-ZnO and 50nm, 100nm nano-Cu contribute to the overall response at the EC50 levels. The particulate forms for 150nm, 200nm and 900nm ZnO SMPs and rod-shaped 78nm nano-Cu mainly affected the soil microbial metabolic potential, while the Cu ions released from spherical 25nm nano-Cu, 500nm Cu SMPs and Pb ions released from perovskites mainly described the effects to bacterial communities. Our results indicate that the dynamic exposure of ENMs and relative contributions of particles and ions require consideration in order to pursue a naturally realistic assessment of environmental risks of metal-based ENMs
Excitations of Ellipsoid Packings near Jamming
We study the vibrational modes of three-dimensional jammed packings of soft
ellipsoids of revolution as a function of particle aspect ratio and
packing fraction. At the jamming transition for ellipsoids, as distinct from
the idealized case using spheres where , there are many
unconstrained and non-trivial rotational degrees of freedom. These constitute a
set of zero-frequency modes that are gradually mobilized into a new rotational
band as increases. Quite surprisingly, as this new band is
separated from zero frequency by a gap, and lies below the onset frequency for
translational vibrations, , the presence of these new degrees of
freedom leaves unaltered the basic scenario that the translational spectrum is
determined only by the average contact number. Indeed, depends
solely on coordination as it does for compressed packings of spheres. We also
discuss the regime of large , where the two bands merge.Comment: 6 pages, 4 figure
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