analyzing nutritional impacts of policies an empirical study for malawi summary widespread malnutrition in developing countries calls for appropriate strategies presupposing good knowledge about nutritional impacts of policies little previous work has been carried out in this direction especially with respect to micronutrients we use representative household data from malawi and develop a demand systems approach to estimate income and price elasticities of food demand and nutrient consumption these estimates are applied for policy simulations given multiple nutritional deficiencies income related policies are better suited than price policies to improve nutrition while consumer price subsidies for maize improve calorie and mineral consumption they can worsen vitamin consumption in urban areas

the energy ladder theoretical myth or empirical truth results from a meta analysis abstract modern fuels are an important enabler of social and economic development still over 2 billion people rely on traditional biomass for their daily energy needs to overcome the negative effects of traditional energy on human health and the environment and to enhance the livelihood conditions of the poor a transition towards cleaner and more efficient forms of energy is needed understanding household fuel choice and fuel switching behaviour is of vital importance in search for policies to support such a transition process this paper adds to the existing energy transition literature in two ways first we provide a novel conceptual framework to analyze the decision environment underlying energy and fuel choices second we apply this framework in a meta analysis of existing choice models investigating energy switching and stacking behaviour in urban and rural areas in developing countries the meta analysis shows that socio economic household characteristics appear to receive most attention so far in identifying groups of fuel users while relatively little information is available on the impact of the external decision context on household energy choices

a note on merton s optimum consumption and portfolio rules in a continuous time model in the paper optimum consumption and portfolio rules in a continuous time model by r c merton j econ theory 3 1971 373 413 solutions obtained in cases when marginal utility at zero consumption is finite are not feasible while they do satisfy the hamilton jacobi bellman equations they do not represent appropriate value functions because the boundary behavior near zero wealth is not satisfactorily dealt with in this note we specify the boundary behavior and characterize optimal solutions journal of economic literature classification numbers 022 213

policies for a sustainable biomass energy sector in malawi enhancing energy and food security simultaneously summary biomass energy still dominates the energy sector in sub saharan africa in particular as the main cooking energy source in rural and urban areas the strong linkages to food security and the environment place biomass energy at the heart of sustainable development a fact that is largely ignored by policy makers in favor of modern energy at the same time population and gdp growth are exacerbating already existing supply demand imbalances in highly populated countries such as malawi these trends make it imperative to identify policy interventions that promote sustainable biomass energy while simultaneously considering linkages with other sectors we use new data on demand and supply for biomass energy in malawi and develop a model that estimates fuelwood demand based on actual diets and project demand in future years we simulate how demand side interventions in the form of improved cookstoves affect biomass demand and built a behavioral model to analyze the potential of agroforestry for promoting a sustainable biomass energy sector in malawi our findings show that policy measures aimed at increasing cooking efficiency are not enough to decrease demand for cooking energy due to high population growth supply side interventions like agroforestry on the other hand will not only increase sustainable supply but can also enhance food security and protect the environment we find that biomass energy can be inherently sustainable and should be an integral part of every energy sector strategy in developing countries as well as of the sustainable development goals

future energy development in tanzania the energy costs of urbanization abstract this paper utilizes the detailed energy balance data developed as part of the tanzania urban energy project to examine future energy use in tanzania the energy costs of urbanization are shown to be quite substantial national energy balances demonstrate that the urban areas make up a large share of the consumption of all fuels except woodfuel as urbanization continues into the future it will be accompanied by dramatic increases in the consumption of petroleum fuels electricity and charcoal for example using base case or business as usual assumptions over a planning period stretching from 1990 to 2010 every 1 increase in the level of urbanization can be expected to lead to a 12 increase in electricity consumption a 14 increase in the consumption of all petroleum fuels and a 14 increase in the consumption of charcoal finally the paper examines different energy policy options which are consistent with the stated national energy policy after the examination of a set of ambitious policy efforts a set of feasible policies are tested and shown to have a significant impact on the goals of improving efficiency obtaining the desirable energy consumption profile and conserving indigenous woodfuel resources

dynamic asset allocation when bequests are luxury goods abstract luxury bequests impart systematic effects of age to an investor s optimal allocation the expected percentage allocation to equities rises throughout retirement when bequests are luxuries the marginal utility of bequests declines more slowly than the marginal utility of consumption this is essentially lower risk aversion as a retiree approaches death her expected remaining lifetime utility is increasingly composed of bequest utility and thus generates progressively lower risk aversion a retiree responds by increasingly favoring the higher return risky asset compared to standard preferences luxury bequests elevate a retiree s average exposure to the risky asset but the difference is small in early retirement

labor shortages on small landholdings in malawi implications for policy reforms abstract a simple linear programming model of representative smallholder households is used to investigate the sources of relative scarcity of labor and land in malawi the paradox of on farm labor shortages on small landholdings can be explained by the multiple constraints smallholders face these multiple constraints including lack of finance concerns for food security and others lead to suboptimal allocations of household resources in turn the low returns to labor and land contribute to household food insecurity and a vicious cycle of poverty the findings of the paper provide a clear signal to policymakers and research and extension institutions that these constraints are all linked and addressing one cannot be effective without addressing the others

explicit solution of a general consumption portfolio problem with subsistence consumption and bankruptcy this paper solves a general continuous time single agent consumption and portfolio decision problem with subsistence consumption in closed form the analysis allows for general continuously differentiable concave utility functions the model takes into consideration that consumption must be no smaller than a given subsistence rate and that bankruptcy can occur thus the paper generalizes the results of karatzas lehoczky sethi and shreve 1986

reassessing the energy ladder household energy use in maun botswana abstract in the context of sub saharan africa s rapid urbanization improved insight into urban energy use is increasingly important based on the predictions of energy transition theory a regional shift from biomass to modern fuels has long been expected to occur in tandem with urban growth however trends observed in the region s towns and cities have often not followed such patterns and fuelwood continues to be important in most areas this paper examines the practical relevance of transition theory using a recent case study conducted by the authors in maun botswana and results previously reported in the literature it finds that despite the long term link between socio economic development and increased modern fuel consumption at the national scale the notion of transition does not accurately reflect ongoing energy use patterns at lower levels of aggregation this is chiefly because its model of household fuel switching largely dismisses the importance of active and strategic decision making by urban consumers and their responsiveness to structural factors such as relative fuel prices as the botswana case illustrates this weakness can significantly distort expectations and policies around urban fuelwood use

modeling choice of fuelwood source among rural households in malawi a multinomial probit analysis abstract this paper addresses two questions what determines household s choice of fuelwood source and what are the environmental consequences of fuelwood collection choices we address these questions by estimating the multinomial probit model using survey data for households surrounding chimaliro and liwonde forest reserves in malawi after controlling for heterogeneity among households we find strong substitution opportunities across fuelwood collection sources attributes of the fuelwood sources size and species composition and distance to the sources are the most important determinants of fuelwood choice further results show that customary managed forests generate environmental benefits by reducing pressure on both plantation forests and forest reserves these findings support the need to strengthen community based institutions to manage local forest resources

optimal consumption and portfolio policies when asset prices follow a diffusion process abstract we consider a consumption portfolio problem in continuous time under uncertainty a martingale technique is employed to characterize optimal consumption portfolio policies when there exist nonnegativity constraints on consumption and on final wealth we also provide a way to compute and verify optimal policies our verification theorem for optimal policies involves a linear partial differential equation unlike the nonlinear partial differential equation of dynamic programming the relationship between our approach and dynamic programming is discussed we demonstrate our technique by explicitly computing optimal policies in a series of examples in particular we solve the optimal consumption portfolio problem for hyperbolic absolute risk aversion utility functions when the asset prices follow a geometric brownian motion the optimal policies in this case are no longer linear when nonnegativity constraints on consumption and on final wealth are included by these examples one can see that our approach is much easier than the dynamic programming approach

the forbidden fuel charcoal urban woodfuel demand and supply dynamics community forest management and woodfuel policy in malawi abstract this article examines woodfuel policy challenges and opportunities in malawi two decades after woodfuel crisis narratives and counter narratives a nuanced examination of woodfuel supply demand use and markets illuminated options to turn stagnant policies based on charcoal bans and fuel substitution into proactive realistic ones acknowledging woodfuel dominance and its socio economic importance findings revealed growing spatially differentiated woodfuel deficits in southern and central malawi and around blantyre zomba and lilongwe cities poverty limited electricity access reliability and generation exacerbated by tariff subsidies and complex fuel allocation decisions restricted energy ladder transitions from woodfuels to electricity producing an enduring urban energy mix dominated by charcoal thereby increasing wood consumption diverse socio political interests prevented lifting of the charcoal ban despite progressive forest laws despite implementation challenges lessons already learnt efficiency and poverty reduction arguments limited government capacity growing illegal production of charcoal in forest reserves and its staying power make targeted community based forest management cbfm approaches more practical for regulated commercial production of woodfuels than the status quo new differentiated policies should include commercial woodfuel production and licensing for revenue and ecological sustainability under cbfm or concessions within and outside selected reserves an enterprise based approaches for poverty reduction smallholder private tree growing woodfuel energy conserving technologies improved electricity supply and agricultural productivity

wealth risk and activity choice cattle in western tanzania abstract imperfect credit markets force households to use their savings for investment profitable activities often require lumpy investments limiting entry by poorer households resulting in increasing welfare differences in tanzania cattle are a profitable but lumpy investment and a liquid asset for consumption smoothing richer households own substantial cattle herds while poorer households specialize in low return low risk activities a dynamic programming model and simulations are presented to analyze entry into asset accumulation under income risk the evidence suggests that households with lower endowments are less likely to own cattle and returns to their endowments are lower

optimal dynamic tax evasion abstract we study optimal dynamic tax evasion in the framework proposed by lin and yang 2001 and dzhumashev and gahramanov 2011 with some modifications a more flexible utility function a more realistic audit process and a penalty function which can be defined both on evaded income and evaded taxes in the former case the elasticity between tax rate and tax evasion is positive unless the subsistence consumption level is higher than a given threshold in the latter case the relationship is usually negative but the value of elasticity depends on the form of absolute risk aversion in particular we show that for increasing relative risk aversion for a tax rate higher than 50 the elasticity may even become positive us data are consistent with irra preferences

poverty and distributional effects of carbon pricing in low and middle income countries a global comparative analysis abstract even though concerns about adverse distributional implications for the poor are one of the most important political challenges for carbon pricing the existing literature reveals ambiguous results for this reason we assess the expected incidence of moderate carbon price increases for different income groups in 87 mostly low and middle income countries building on a consistent dataset and method we find that for countries with per capita incomes of below usd 15 000 per year at ppp adjusted 2011 usd carbon pricing has on average progressive distributional effects we also develop a novel decomposition technique to show that distributional outcomes are primarily determined by differences among income groups in consumption patterns of energy rather than of food goods or services we argue that an inverse u shape relationship between energy expenditure shares and income explains why carbon pricing tends to be regressive in countries with relatively higher income since these countries are likely to have more financial resources and institutional capacities to deal with distributional issues our findings suggest that mitigating climate change raising domestic revenue and reducing economic inequality are not mutually exclusive even in low and middle income countries

energy consumption in rural china a household model for three villages in jiangxi province abstract in china fuelwood and coal are the most important energy sources for rural households in poor areas along with population and economic growth excessive fuelwood collection is a major cause of deforestation burning coal contributes to environmental problems such as air pollution acid rain and greenhouse gas emissions the purpose of this article is to analyze factors determining choice of energy source and labor input into fuelwood collection in poor forest rich regions and to provide policy recommendations on ways to affect these choices to this end a nonseparable household model reflecting choices in labor allocation and energy demand of rural households is estimated from available data for three villages in a poor forest rich region in jiangxi province southeast china innovative aspects of this article are the analyses of factors driving household substitution between forest and non forest fuels and of dissimilarities in household responses under different market access conditions

consumption and investment under constraints abstract we study the problem of an investor who is endowed with a deterministic level of initial capital and must use this endowment to consume and invest in a financial market the investor is constrained to consume at a minimum rate throughout the period and has to maintain his wealth over a lower bound at all times both these minimal requirements may be stochastic an example of such an investor would be an investment firm with cash flow commitments and subject to regulatory capital constraints in addition the investor s portfolio choices are limited to a convex constraint set this accounts for prohibitions on short selling and incompleteness of the market using the space of associated risk neutral measures we construct portfolio policies to support target consumption investment plans we also consider a utility maximization problem for the investor and provide a related dual minimization problem over the space of measures the solution of this dual problem provides a price system under which the investor can solve for his optimal consumption investment policy in general however we are not assured of existence due to the fact that the investor s minimal requirements may themselves be beyond the span of the constrained portfolios

a double hurdle model of cigarette consumption this paper shows the importance of the double hurdle approach for modelling individuals cigarette consumption using data from the uk general household survey and argues that participation and consumption should be treated as separate individual choices the likelihood function for the full double hurdle is derived and it is shown how restrictions on the stochastic specification of the model and auxillary information which identifies ex smokers allow it to be decomposed the empirical results highlight the value of the sample separation information and the need to model starting and quitting as separate decisions

farmers perceptions and adoption of new agricultural technology evidence from analysis in burkina faso and guinea west africa economists investigating consumer demand have accumulated considerable evidence showing that consumers generally have subjective preferences for characteristics of products and that their demand for products is significantly affected by their perceptions of the product s attributes however the role of farmers preferences in adoption decisions have received very limited attention in adoption studies conducted by economists this paper tests the hypothesis that farmers perceptions of technology characteristics significantly affect their adoption decisions the analysis conducted with tobit models of modern sorghum and rice varietal technologies in burkina faso and guinea respectively strongly supports this hypothesis our results provide a strong case for future adoption studies to expand the range of variables used away from the broad socio economic demographic and institutional factors to include farmers subjective perceptions of the characteristics of new agricultural technologies