smallholders land access in sub saharan africa a new landscape while scholars long recognized the importance of land markets as a key driver of rural non farm development and transformation in rural areas evidence on the extent of their operation and the nature of participants remains limited we use household data from 6 countries to show that there is great potential for such markets to increase productivity and equalize factor ratios while rental markets transfer land to land poor and labor rich producers their operation and thus impact may be constrained by policy restrictions their functioning may also be constrained by ill defined or insecure rights that may arise from failure to fully compensate existing rights in cases of expropriation a failure to implement more broadly land policies or to do so in a gender sensitive manner methodological and substantive conclusions are derived

using a policy mix for pollution control a review of economic literature this article provides a review of economic studies analyzing the use of multiple policies a socalled policy mix to cope with single pollution problems to guide and structure the review an analytical framework is developed and applied the framework integrates transaction costs into the analysis of pollution problems and policies to overcome them moreover it understands a pollution externality not only as a market failure but more generally as the failure of private governance structures based on this insight two rationales for using a policy mix are identified first a policy mix may help to correct for multiple reinforcing failures of private governance structures such as pollution externalities and technological spillovers second a policy mix can be employed if the implementation of single first best policies brings about high transaction costs e g when marginal pollution damages are heterogeneous or polluters are unlikely to comply with the policy for each rationale the relevant literature is presented based on the review avenues for future research are identified

the socially optimal recycling rate evidence from japan this paper estimates the average social cost of municipal waste management as a function of the recycling rate social costs include all municipal costs and revenues costs to recycling households to prepare materials estimated with an original method external disposal costs and external recycling benefits results suggest average social costs are minimized with recycling rates well below observed and mandated levels in japan cost minimizing municipalities are estimated to recycle less than the optimal rate these results are robust to changes in the components of social costs indicating that japan and perhaps other developed countries may be setting inefficiently high recycling goals

economic efficiency effects of alternative policies for reducing waste disposal abstract reducing the amount of municipal solid waste that is disposed of has become an important policy goal previous research argued that a virgin material tax offered an efficient method of meeting this goal and it continues to be considered as a policy option today this paper demonstrates however that a virgin material tax is not an efficient method of reducing waste but that an alternative policy a combined disposal tax and reuse subsidy is the combined disposal tax and reuse subsidy is theoretically consistent with unit based household charges for waste disposal but may have advantages in some situations

scrap prices waste and recycling policy this study examines the effect of waste and recycling policy on scrap prices and the importance of scrap price feedbacks as a determinant of policy costs price effects and direct and indirect channels of waste reduction are decomposed for deposit refund advance disposal fee and recycling subsidies scrap price feedbacks decrease the cost of advance disposal fees increase the cost of recycling subsidies and have an ambiguous effect on the cost of deposit refund simulation analysis finds that scrap price feedbacks substantially affect the costs of the policies and alter the ranking of instruments jel q53 q58

gender social norms and household production in burkina faso abstractempirical studies of intrahousehold allocation have revealed that in many instances gender is an important determinant in the allocation of resources within the household yet within the theoretical literature why gender matters within the household remains an open question in this article we propose a simple model of intrahousehold allocation based on a particular social institution for the organization of agricultural production practiced among certain ethnic groups in west africa we highlight how this institution while resolving certain problems of commitment and informational asymmetry can also lead to a gendered pattern in the allocation of productive resources and consumption within the household using a survey of agricultural households in burkina faso we show consistent with this theory that plots owned by the head of the household are farmed more intensively and achieve higher yields than plots with similar characteristics owned by other household members male and female fam

on the dynamics of recycling and natural resources we study the dynamic impact of recycling through its effect on the production set of the economy and its relationship with natural resources the contribution of renewable and recyclable resources for sustainability is studied although in the short run recycling may alleviate resource scarcity in the long run it is not enough to compensate for the exhaustibility of non renewable resources and the possibility of obtaining non decreasing output paths crucially depends on the extent to which production rests on renewable resources furthermore recycling interacts with natural resource growth surprisingly not always favoring sustainability the production and recycling function is a generalization of the traditional production function providing an integrated view of regular production and recycling and representing the production set of the economy when a recycling technology is available

closing the gap a learning algorithm for lost sales inventory systems with lead times we consider a periodic review single product inventory system with lost sales and positive lead times under censored demand in contrast to the classical inventory literature we assume the firm d

converting technology to mitigate environmental damage there are many situations where policy makers would like to induce firms to make a major discrete conversion in production technology to help the environment this paper examines how heterogeneity in the operating condition of firms plant and equipment which cannot be observed by policy makers can affect the choice between incentives to encourage conversion to a cleaner technology by relating different conditions of firms plant and equipment to production costs extent of environmental damage and cost of conversion to a cleaner technology we show when a perfectly discriminating incentive to encourage conversion is not feasible in addition we show that firms with plant and equipment in better condition will convert their technology to mitigate their environmental damage and firms with plant and equipment in poorer condition will not this and a series of additional results lead to conditions under which an administratively simple uniform lump sum incentive to switch to cleaner technology is preferable to one based on output these results and conditions extend to cases where there are network externalities in conversion and where there is strategic timing in firms choice of when to convert

environmental and gender impacts of land tenure regularization in africa pilot evidence from rwanda although increased global demand for land has led to renewed interest in african land tenure few models to address these issues quickly and at the required scale have been identified or evaluated the case of rwanda s nation wide and relatively low cost land tenure regularization program is thus of great interest this paper evaluates the short term impact some 2 5 years after completion of the pilots undertaken to fine tune the approach using a geographic discontinuity design with spatial fixed effects three key findings emerge from the analysis first the program improved land access for legally married women about 76 percent of married couples and prompted better recordation of inheritance rights without gender bias second the analysis finds a very large impact on investment and maintenance of soil conservation measures this effect was particularly pronounced for female headed households suggesting that this group had suffered from high levels of tenure insecurity which the program managed to reduce third land market activity declined allowing rejection of the hypothesis that the program caused a wave of distress sales or widespread landlessness by vulnerable people implications for program design and policy are discussed

tenure insecurity gender low cost land certification and land rental market participation in ethiopia abstract there is a renewed interest in whether land reforms can contribute to market development and poverty reduction in africa this paper assesses effects on the allocative efficiency of the land rental market of the low cost approach to land registration and certification of restricted property rights that was implemented in ethiopia in the late 1990s four rounds of a balanced household panel from 16 villages in northern ethiopia are analysed showing that land certification initially enhanced land rental market participation of potential tenant and landlord households especially those that are headed by females

on the suboptimality of s 1 s lost sales inventory policies abstract this paper considers replenishment policies for the continuous review inventory model with poisson demand a fixed lead time on replenishment and lost sales during a stockout there is a time dependent stockholding cost and a cost per unit of sale lost but there is no or negligible cost associated with placing a replenishment order the standard policy is to specify a maximum stock level s and place a replenishment order whenever a demand occurs and is met this is commonly referred to as an s 1 s policy it is shown that there are other replenishment policies which give lower cost solutions in fact it is demonstrated that an s 1 s policy can never be optimal if s 2

garbage recycling and illicit burning or dumping abstract with garbage and recycling as the only two disposal options we confirm prior results that the optimal curbside fee for garbage collection equals the direct resource cost plus external environment cost when illicit burning or dumping is a third disposal option that cannot be taxed directly the optimal curbside tax on garbage changes sign the optimal fee structure is a deposit refund system a tax on all output plus a rebate on proper disposal through either recycling or garbage collection the output tax helps achieve the first best allocation even though it affects the choice between consumption and untaxed leisure

asymptotic optimality of order up to policies in lost sales inventory systems we study a single product single location inventory system under periodic review where excess demand is lost and the replenishment lead time is positive the performance measure of interest is the long run average holding cost and lost sales penalty cost for a large class of demand distributions we show that when the lost sales penalty becomes large compared to the holding cost the relative difference between the cost of the optimal policy and the best order up to policy converges to zero for any given cost parameters we establish a bound on this relative difference numerical experiments show that the best order up to policy performs well yielding an average cost that is within 1 5 of the optimal cost when the ratio between the lost sales penalty and the holding cost is 100 we also propose a heuristic order up to level using two newsvendor expressions in our experiments the cost of this order up to policy is 2 52 higher on an average than the best order up to policy

revaluing the hierarchy of paper recycling this article revalues the hierarchy of paper waste management policies in a dynamic general equilibrium model incineration material recycling and the distinction between non renewable fossil fuels and renewable forest assets are incorporated by comparing the first order conditions from the command optimum with the conditions from the market model it is discovered that the unregulated market fails to create an optimal resource allocation to see how the market behaves in absence of environmental policy compared to the first best solution a numerical model is used pigouvian taxes and subsidies are derived to correct for the externalities

some insights regarding the optimal reorder period in periodic review inventory systems abstract the periodic review inventory system is not only pervasive but also has an extensive literature dealing with various aspects from its theoretical underpinnings through to its performance however the selection of the best review period and its behaviour with respect to basic inventory parameters such as demand and supply variability appears to be poorly understood in this paper we treat the normal and gamma distributions which are probably the two most commonly used distributions of demand over the key protection time interval in a periodic review system we show that the total cost function is not necessarily well behaved as a function of the review period in particular it can be non convex which complicates the determination of the best value of the review interval also we demonstrate and explain how the best review period changes as the values of various parameters are modified some of these changes are initially counterintuitive in nature managerially oriented interpretations should also be helpful to organisations seeking improvement in inventory system performance

upstream pollution downstream waste disposal and the design of comprehensive environmental policies abstract many policymakers are shifting their focus from media specific pollution problems to product specific life cycle environmental problems in this paper we develop a model of production and consumption that incorporates life cycle externalities and use it to solve for alternative policies to achieve a social optimum in general we find that no single instrument can solve multiple problems contrary to what some observers have suggested however we find that there are alternative ways of reaching the social optimum we also discover that an integrated approach to policy appears to be important no matter what policy options are adopted and finally we find that there is only a limited role for so called product life cycle assessments

inventory control in directed networks a note on linear costs we consider periodic review inventory control problems in directed networks primary examples of which are distribution systems and assembly systems external demand could occur at each node when inventory is insufficient to meet requirements at a node a portion of this demand is backordered and the remaining is lost external demands as well as lead times for inventory purchase assembly and transportation are stochastic in each period linear sales revenues and the following costs all linear are charged at each node a inventory purchase assembly transfer cost to receive inventory b holding cost c backorder cost and d lost sales cost when the objective function of interest is a discounted sum of profits over a finite planning horizon it is shown that the sales prices and the inventory purchase assembly transfer cost parameters can be assumed to be zero without loss of generality the result is proved for every realization of demands and lead times some extensions to these results are discussed during this process we also generalize the concept of echelon inventories to directed networks

lost sales problems with stochastic lead times convexity results for base stock policies we consider a single location inventory system with periodic review and stochastic demand it places replenishment orders to raise the inventory position that is inventory on hand plus inventory in transit to exactly s at the beginning of every period the lead time associated with each of these orders is random however the lead time process is such that these orders do not cross demand that cannot be met with inventory available on hand is lost permanently we state and prove some sample path properties of lost sales inventory on hand at the end of a period and inventory position at the end of a period as functions of s the main result is the convexity of the expected discounted sum of holding and lost sales costs as a function of s this result justifies the use of common search procedures or linear programming methods to determine optimal base stock levels for inventory systems with lost sales and stochastic lead times it should be noted that the class of base stock policies is suboptimal for such systems and we are primarily interested in them because of their widespread use

a comparison of public policies for lead recycling policies that encourage recycling may be used to reduce environmental costs from waste disposal because direct restrictions on disposal are difficult to enforce four recycling policies have been advanced i taxes on the use of virgin materials ii deposit refund programs iii subsidies to recycled material production and iv recycled content standards in this article i analyze the structure of these policies and their cost effectiveness in achieving reductions in disposal i then examine the policies in the empirical context of the recycling of lead from automobile batteries in order to calculate the effects of recycling programs i estimate the elasticities for primary and secondary lead supply and demand my results suggest that price based policy mechanisms can be successful in increasing lead recovery and that the difference in efficiency between the four approaches is similar

on the second best policy of household s waste recycling this study analyzes the second best household s waste recycling policy if we assume the first best economy with no illegal disposal or transaction costs then unit pricing an advance disposal fee and a recycling subsidy are required in order to achieve the social optimum such that both the sum of unit pricing and an advance disposal fee and the sum of unit pricing and a recycling subsidy are equal to the marginal disposal cost furthermore the first best outcome can also be obtained by a producer take back requirement system in the real economy however various factors prevent the first best optimal outcome in this study we consider two factors one being the transaction cost associated with a recycling subsidy or refund and the other being illegal disposal by the consumer if a recycling subsidy or a deposit refund system is adopted a transaction cost associated with it will be generated alternatively if unit pricing is adopted some of the consumed goods may be disposed of illegally we show the complete trade off between unit pricing and a recycling subsidy in other words we can not adopt unit pricing and a recycling subsidy simultaneously as a result there are three candidates for the second best policy unit pricing with an advance disposal fee a deposit refund system and a producer take back requirement system which of these three policies is the second best policy will depend on the relative magnitude of the price of a recycled good and the marginal transaction cost associated with a recycling subsidy or the refund in a deposit refund system generally if the price of a recycled good is positive and the marginal transaction cost is relatively high unit pricing with an advance disposal fee is the second best policy however where the price of a recycled good is negative and the marginal transaction cost is relatively high a producer take back requirement system is the second best policy further where the marginal transaction cost is relatively low a deposit refund system is the second best policy regardless of whether the price of a recycled good is positive or negative

gender differences in the relationship between land ownership and managerial rights implications for intrahousehold farm labor allocation abstract recent research has increased interest in the intersection of land tenure and gender roles in african agriculture while formalization of land ownership has been found to have important gender impacts time use and management remain critical to both the productivity of agricultural operations as well as the welfare of household members thus it is important to understand how gender intersects with the relationship between the ownership and operation of plots we use plot level data from nationally representative household surveys in ethiopia and malawi to characterize the structure sole male sole female or joint and domain plot ownership plot management or output management of control over land in each household we then answer the following research questions 1 are there any gender gaps in the degrees of the concordance among different domains of controls and 2 how does the structure of ownership and managerial rights affect labor allocations on plots we find that for both males and females sole managerial rights are most likely to occur in plots owned exclusively by either gender however on jointly owned plots instances of sole planting rights are almost exclusively male we also find that while females supply more of their own labor to plots they control the pattern of own gender bias in labor allocation varies with each structure domain combination the heterogeneity suggests gender inequality analyses related to land rights are sensitive to the choice of domain of control

does international harmonization of environmental policy instruments make economic sense harmonization of the instruments used in environmental policy has beenconsidered necessary to guarantee fair competition in internationalmarkets we examine the economic costs of harmonizing paper recyclingstandards in countries where the urgency of the waste disposal problemsdiffer using data of seven european countries we estimate thetechnologically feasible input combinations of pulp and waste paper forpaper production short term effects of two environmental policy measures minimum content requirement and utilization rate target are analyzed bytranslating the two administrative instruments into taxes and subsidies weshow that the shadow costs of the harmonization vary considerably betweencountries the difference in the domestic availability of waste may explainthe variation and a modification of the policy measures to incorporate thisaspect is suggested

how much of the labor in african agriculture is provided by women the contribution of women to labor in african agriculture is regularly quoted in the range of 60 to 80 percent using individual disaggregated plot level labor input data from nationally representative household surveys across six sub saharan african countries this study estimates the average female labor share in crop production at 40 percent it is slightly above 50 percent in malawi tanzania and uganda and substantially lower in nigeria 37 percent ethiopia 29 percent and niger 24 percent there are no systematic differences across crops and activities but female labor shares tend to be higher in households where women own a larger share of the land and when they are more educated controlling for the gender and knowledge profile of the respondents does not meaningfully change the predicted female labor shares the findings question prevailing assertions regarding substantial gains in aggregate crop output as a result of increasing female agricultural productivity

the profits of power land rights and agricultural investment in ghana we examine the impact of ambiguous and contested land rights on investment and productivity in agriculture in akwapim ghana we show that individuals who hold powerful positions in a local political hierarchy have more secure tenure rights and that as a consequence they invest more in land fertility and have substantially higher output the intensity of investments on different plots cultivated by a given individual corresponds to that individual s security of tenure over those specific plots and in turn to the individual s position in the political hierarchy relevant to those specific plots

inefficiency of male and female labor supply in agricultural households evidence from uganda this article analyzes the efficiency of the intra household allocation of female and male labor inputs in agricultural production in a collective household model spouses optimal on farm labor supply is such that the marginal rate of technical substitution between male and female labor is equated over different crops using the uganda national household survey 2005 06 we test whether this condition holds by estimating production functions and controlling for endogeneity using a method proposed by gandhi navarro and rivers 2009 we find that women are less productive than men that there is more female labor input on low productivity parcels and that men are relatively more productive on female controlled plots compared with male controlled plots total farm output could be higher and pareto improvements could be possible if male labor was reallocated to female controlled plots and or female labor was reallocated to male controlled plots

land tenure and agricultural productivity in africa a comparative analysis of the economics literature and recent policy strategies and reforms summary this paper examines the convergence and divergence of results from economic studies of the relationships between land tenure security and agricultural productivity in africa and how these results have been incorporated into recent agricultural poverty alleviation and land policy documents the paper finds that there are both areas of convergence and divergence in the economics literature similarly the attention given to land tenure and its perceived effects on productivity varies considerably in the policy literature the significant heterogeneity in findings itself suggests that policy responses must pay attention to local context and the overarching macro and sectoral conditions within which tenure systems operate

recovery decisions of a producer in a legislative disposal fee environment the main objectives of the environmental legislation originating from extended producer responsibility epr principle are to lead producers to undertake recovery initiatives for their end of use products and to promote environmentally desirable product design it is still controversial whether current implementations of epr principle are effective in attaining these objectives this study seeks to answer the following questions 1 what is the impact of epr legislation on the product recovery decisions of producers 2 how do the redesign opportunities i e design for disassembly affect the willingness of producers for product recovery 3 how do the investment needs to start recovery practices and the reluctance of producers to allocate sufficient funds for this purpose affect the optimal recovery decisions we use stylized economic models to represent the implementation in practice and solving our models we obtain closed form and numerical solutions that help us to see the impact of various parameters on the optimal decisions of a producer our findings indicate that redesign opportunities encourage producers for more recovery however the reluctance of producers to cover the initial investments may substantially reduce the effectiveness of the legislation and the recovery amounts

product design and efficient management of recycling and waste treatment abstract using a general equilibrium model where material is first extracted then used for producing a consumption good recycled and finally treated to reduce environmental damage we study efficiency restoring policies when one or more of the constituent markets are inactive the material is modeled as being embodied in the output and forms an important aspect of green product design if all markets for embodied material per unit output fail and if recycling benefit exceeds environmental damage the policy instruments needed for green design are a tax on the consumption good supply and a subsidy on the demand for material input

household responses to pricing garbage by the bag this paper estimates household reaction to the implementation of unit pricing for the collection of residential garbage we gather original data on weight and volume of weekly garbage and recycling of 75 households in charlottesville virginia both before and after the start of a program that requires an eighty cent sticker on each bag of garbage this data set is the first of its kind we estimate household demands for the collection of garbage and recyclable material the effect on density of household garbage and the amount of illegal dumping by households we also estimate the probability that a household chooses each method available to reduce its garbage in response to the implementation of this unit pricing program we find that households 1 reduced the weight of their garbage by 14 2 reduced the volume of garbage by 37 and 3 increased the weight of their recyclable materials by 16 we estimate that additional illegal or at least suspicious disposal accounts for 0 42 pounds per person per week or 28 of the reduction in garbage observed at the curb this abstract was borrowed from another version of this item

one without the other behavioural and incentive policies for household waste management this paper provides a review of economic studies that analyses the use of multiple policies to cope with waste management problems we discuss the factors that influence selective sorting behaviour and the most appropriate policies for their promotion based on the works analysed our survey shows the original features of waste as an environmental problem requiring regulation the traditional approach in which decisions respond to rational behaviour particularly cost savings has some limits although not all public policies seem justified we argue that there might be a need for specific policies to promote recycling preferably based on the provision of information to consumers or on behavioural instruments indeed personal factors specific to each individual such as emotions and the influence of social interaction should be taken into account in the development of public policies we review the literature related to different rationales and identify some avenues for future research

greenhouse gas emissions waste and recycling policy abstract this paper examines least cost policies for waste reduction incorporating upstream greenhouse gas externalities associated with the production of consumption goods from various materials in particular we decompose the effect of deposit refund advance disposal fees and recycling subsidies on upstream greenhouse gas emissions we find that the benefits of reducing greenhouse gas emissions are of the same order as or larger than the benefits of reducing solid waste disposal implying larger optimal total waste reduction than previous studies furthermore the least cost intervention levels will be material specific and vary substantially across materials finally despite the reductions in emissions implied by increased recycling rates direct recycling subsidies are more costly and generate less emissions reductions than a deposit refund or advance disposal fee

efficient implementation of collective extended producer responsibility legislation extended producer responsibility epr is a policy tool that holds producers financially responsible for the post use collection recycling and disposal of their products many epr implementations are collective a large collection and recycling network crn handles multiple producers products in order to benefit from scale and scope economies the total cost is then allocated to producers based on metrics such as their return shares by weight such weight based proportional allocation mechanisms are criticized in practice for not taking into account the heterogeneity in the costs imposed by different producers products the consequence is cost allocations that impose higher costs on certain producer groups than they can achieve independently this may lead some producers to break away from collective systems resulting in fragmented systems with higher total cost yet cost efficiency is a key legislative and producer concern to address this concern this paper develops cost allocation mechanisms that

new policies for the stochastic inventory control problem with two supply sources we study an inventory system under periodic review in the presence of two suppliers or delivery modes the emergency supplier has a shorter lead time than the regular supplier but the unit price he offers is higher excess demand is backlogged we generalize the recently studied class of dual index policies veeraraghavan s a scheller wolf 2008 now or later dual index policies for capacitated dual sourcing systems oper res 56 4 850 864 by proposing two classes of policies the first class consists of policies that have an order up to structure for the emergency supplier we provide analytical results that are useful for determining optimal or near optimal policies within this class this analysis and the policies we propose leverage our observation that the classical lost sales inventory problem is a special case of this problem the second class consists of policies that have an order up to structure for the regular supplier here we derive bounds on the optimal order quantity from the emergency supplier in any period and use these bounds for finding effective policies within this class finally we undertake an elaborate computational investigation to compare the performance of the policies we propose with that of dual index policies one of our policies provides an average cost saving of 1 1 over the best dual index policy and has the same computational requirements another policy that we propose has a cost performance similar to the best dual index policy but its computational requirements are lower

continuous review lost sales inventory models with poisson demand a fixed lead time and no fixed order cost abstract this paper considers continuous review lost sales inventory models with no fixed order cost and a poisson demand process there is a holding cost per unit per unit time and a lost sales cost per unit the objective is to minimise the long run total cost base stock policies are in general sub optimal under lost sales the optimal policy would have to take full account of the remaining lead times on all the orders currently outstanding and such a policy would be too complex to analyse let alone implement this paper considers policies which make use of the observation that for lost sales models base stock policies can be improved by imposing a delay between the placement of successive orders the performance of these policies is compared with that of the corresponding base stock policy and also with the policy of ordering at fixed and regular intervals of time

gender agricultural production and the theory of the household virtually all models of the household assume that the allocation of resources is pareto efficient within many african households agricultural production occurs on many plots controlled by different members of the household pareto efficiency implies that factors should be allocated efficiently across these plots i find in contrast that plots controlled by women are farmed much less intensively than similar plots within the household controlled by men the estimates imply that about 6 percent of output is lost because of inefficient factor allocation within the household the paper suggests a new approach to modeling intrahousehold allocation consistent with the empirical results

the effect of bottle laws on income new empirical results eleven us states have bottle laws deposit refund programs that combine a consumption tax with a recycling rebate when states set the bottle deposit low enough it becomes a tax on high wage earners for whom the opportunity cost of their time prevents them from returning containers for their deposit however this bottle deposit will still be high enough that harvesting recyclables provides employment for low wage earners using individual data on observed cash recycling behavior this paper shows that an unintended consequence of bottle laws is that they have the potential to increase the incomes of very low wage workers

extended producer responsibility instruments and innovation in eco design an exploration through a simulation model abstract this paper presents an agent based simulation model that models both economical and physical relations between firms recyclers and consumers this framework allows an investigation into the connection between physical environmental variables waste flows virgin material flows and economic decisions of agents in the product chain i e firms innovation strategies consumers choices and development of recycling activities the paper highlights the value of using agent based modeling as an operational tool to investigate the effect of waste prevention policy on economic and technological decisions of agents we focus on three types of extended producer responsibility epr instruments which are recycling fees tax subsidy and norms the simulation results show that the impact of each instrument depends on the policy design in particular on the level of stringency and on the reward system which is implemented we show that only tax subsidy systems and stringent norms can lead to radical innovations and to significant changes in product designs in the case of tax subsidy the impact relies more on an innovation effect while in the case of norm it mainly relies on a selection effect

environmental regulation of households an empirical review of economic and psychological factors abstract the literature on sustainable consumption and environmental regulation of household behavior is dominated by conceptual and normative approaches as a result many suggestions lack a firm empirical basis to overcome this deficiency econometric studies in three areas of environmentally relevant activities of households are reviewed residential use of energy generation of solid waste and recycling and residential use of water next to price and income elasticities attention is devoted to individual socio economic features and psychological factors such as attitudes knowledge perceptions and values potential psychological determinants and related insights are further examined by discussing a range of representative and illustrative statistical psychological studies of environmental behavior one important general finding is that there are very few empirical studies that systematically combine socio economic and psychological determinants a range of insights for environmental policy is derived and research recommendations are offered

optimal policies for solid waste disposal taxes subsidies and standards abstract pricing trash collection and disposal services can be politically unpopular and may lead to increased illegal disposal of trash several studies have shown that deposit refund systems can act like disposal charges without the illegal disposal problem and thus can generate an optimal amount of solid waste disposal we assess the efficiency implications of an alternative policy currently in use in some states in the u s and considered at the federal level recycled content standards these are requirements that a certain fraction of total material use in production be comprised of secondary materials we find that such standards by themselves cannot generate the optimal amount of disposal but must be combined with additional taxes on both the final product and other inputs to production moreover the information requirements for setting the optimal standards and accompanying taxes are high the deposit refund approach would be preferred in most cases

technical note linear inflation rules for the random yield problem analysis and computations in this paper we propose a simple heuristic approach for the inventory control problem with stochastic demand and multiplicative random yield our heuristic tries to find the best candidate within a class of policies that are referred to in the literature as the linear inflation rule lir policies our approach is computationally fast easy to implement and intuitive to understand moreover we find that in a significant number of instances our heuristic performs better than several other well known heuristics that are available in the literature

the roles of land tenure reforms and land markets in the context of population growth and land use intensification in africa this article reviews the past and potential future roles of land tenure reforms and land markets in sub saharan africa ssa as responses to population growth in the process of land use intensification and livelihood transformation the farm size distribution and the existence of an inverse relationship ir between farm size and land productivity in ssa and the implications of this relationship for efficiency and equity are investigated more secure property rights and removal of restrictions on land markets have the potential to create both efficiency and equity benefits but there are high risks of elite capture of large land areas with inefficient and inequitable outcomes this situation is the case not only in land abundant areas but also in urban and peri urban areas where increasingly larger proportions of people will make their living increasing population pressure in densely populated rural areas contributes to more rapid rural urban migration and creating alternative livelihood opportunities for the migrating youth population is essential to achieving economic development with social stability

product servicing for lifespan extension and sustainable consumption an optimization approach abstract sustainable consumption has been defined as the consumption of goods and services that meet basic needs and quality of life without jeopardizing the needs of future generations oecd 2002 lifespan extension of durable products underpins sustainable consumption this paper describes a novel approach to extend product lifespans by using product servicing that conceptualizes the interactions of a producer a policy maker and multiple consumer segments having different price demand relationships we propose a multi period mathematical optimization model that maximizes the producer s profit while optimizing the prices of different servicing options production quantities and inventory levels a computational study elicits several insights about how the optimal production or alternatively consumption quantities are affected by the introduction of product servicing and the effects of various product characteristics and government incentive or penalty levels on producer s profitability and on product servicing decisions we conclude that quantitative optimization models are useful for evaluating the impacts of different regulatory policies assessing the benefits of offering product servicing options and investing in design for durability and serviceability

efficient waste management policies and strategic behavior with open borders during the last decade waste management has been characterized by two main trends the growth of international trade of waste materials and the introduction of extended producer responsibility epr as a policy instrument in this paper a two country stylized model with imperfect competition in the recycling market is used to address two research questions first how do epr recycling targets interact with other policy instruments such as taxes on recycling residues and excise duties second how does strategic behavior of national policy makers influences the use of policy instruments the model demonstrates that a combination of epr with other instruments is needed to achieve the first best outcome when governments do not coordinate policies across borders strategic behavior may lead to a race to the bottom for taxes on recycling residues conversely strategic behavior may lead to a counter intuitive race to the top for excise duties and epr recycling targets it is shown that these instruments are not only used to stimulate waste prevention but also to extract rents from foreign recyclers

dynamic efficiency of extended producer responsibility instruments in a simulation model of industrial dynamics this article presents an original approach to the impact of extended producer responsibility instruments for waste prevention upon firms innovative strategies and market structure our analysis is based on a stylised framework of waste prevention developed by brouillat in this framework products are modelled as multi characteristic technologies whose evolution depends on firms innovation strategies and on the interactions with consumers and postconsumption activities recycling this stylised framework has been adapted to explore the impact of waste prevention instruments upon industrial dynamics and more particularly upon firms innovative strategies and upon the evolution of products characteristics and market structure we focus on two types of policy instruments recycling fees and norms for each instrument we will consider different policy designs in order to study their effects on industrial dynamics the main contribution of this article is to show how this type of simulation model can be used to explore the impact of waste prevention policy instruments on the technological evolution of products on innovation strategy and on the evolution of firms market shares the introduction of policy instruments in a simulation agent based model of industrial dynamics enables us to analyse more thoroughly how different policy designs can modify the dynamics of the system and more particularly how the incentives and the constraints linked to the policy instruments under consideration shape market selection copyright 2012 the author 2011 published by oxford university press on behalf of associazione icc all rights reserved oxford university press

pure and modified base stock policies for the lost sales inventory system with negligible set up costs and constant lead times abstract the studied inventory system with continuous review has an easily computed optimal s 1 s policy when unsatisfied demands are backlogged we assume that unsatisfied demands are lost and then it is also easy to compute the best s 1 s policy but as demonstrated by roger hill at the isir symposium in 1996 this pure base stock policy can never be optimal if s 2 our focus is on periodic review we use erlang s loss formula to derive approximate expressions for the stockout probability and the average cost these expressions are used to approximate the average cost and to compute a good base stock we formulate and implement a markov decision model to find the optimal replenishment policy the model is solved by a policy iteration algorithm because the optimal policy is often rather complicated we introduce modified base stock policies they are specified by a pair s t where s is the base stock and t is a lower bound for the number of review periods between review epochs in which placing a replenishment order is permitted a simple one has s equal to the base stock computed from erlang s formula and fixes t as the largest integer which is less than or equal to the ratio of the number of review periods per delivery period and s our numerical examples show that the simple modified base stock policy provides most of the cost reduction which can be obtained by replacing the best pure base stock policy by the optimal policy

land tenure and investment incentives evidence from west africa abstract the existing literature on the relationship between property rights in land and agricultural investment in africa has given results that are often confusing and contradictory i make two clarifying contributions to this literature first i pull together existing studies and investigate whether the results they find have been affected by research methods or local contexts studies with small sample sizes those that use binary investment measures and those that control for household fixed effects are less likely to find a statistically significant link between land tenure and investment self reported tenure security has been a poor predictor of investment outcomes second i test for a relationship between land tenure and agricultural investment in nine data sets from west africa while the link between tenure and investment is significant for fallow and tree planting it is less robust for labor use and other inputs such as manure or chemical fertilizer

land markets and land access among female headed households in northwestern tanzania summary land markets can potentially improve land access for female headed households if markets exhibit less restrictive gender norms around land ownership as compared with non market based systems of allocation at the same time land markets may not operate in a gender neutral manner with restrictions beyond the market continuing to influence the options of female headed households using both qualitative data and household survey data collected in 2014 and 2015 this paper explores the extent and manner in which female heads participate in the sales and rental markets in northwestern tanzania a qualitative analysis reveals that female heads do engage with the market although they find it most difficult to mobilize the necessary capital to participate as buyers or renters women also seem to face unique restrictions on selling land regression results show that female heads use the market to augment a small land endowment left from their marriage and this is particularly true for divorced or separated women however female headed households remain somewhat marginalized in terms of market participation our study shows that female heads in tanzania are far from sidelined in the land market though the rules of market engagement are decidedly nuanced

the two part instrument in a second best world abstract standard pigovian tax theory has been extended in two directions first many polluting activities are difficult to tax because they are not market transactions and so recent papers have shown that the same effects can be achieved by use of a two part instrument 2pi a tax on output or income and a subsidy for clean alternatives to pollution it is a generalization of a deposit refund system drs second a different literature concerns the second best pollution tax in the presence of other tax distortions here we combine the two extensions by looking at the second best 2pi when government needs revenue is the deposit larger and the rebate smaller we find explicit solutions for each tax and subsidy in a general equilibrium model with other tax distortions and we compare these to the rates in a first best model the tax subsidy combination is explained in terms of a tax effect an environmental effect and a revenue effect the model allows for flexible interpretation to show various applications of the 2pi we also discuss important caveats

managing inventory with multiple products lags in delivery resource constraints and lost sales a mathematical programming approach this paper develops an order up tos inventory model that is designed to handle multiple items resource constraints lags in delivery and lost sales without sacrificing computational simplicity mild conditions are shown to ensure that the expected average holding cost and the expected average shortage cost are separable convex functions of the order up to levels we develop nonparametric estimates of these costs and use them in conjunction with linear programming to produce what is termed the lp policy the lp policy has two major advantages over traditional methods first it can be computed in complex environments such as the one described above and second it does not require an explicit functional form of demand something that is difficult to specify accurately in practice in two numerical experiments designed so that optimal policies could be computed the lp policy fared well differing from the optimal profit by an average of 2 20 and 1 84 respectively these results compare quite favorably with the errors incurred in traditional methods when a correctly specified distribution uses estimated parameters our findings support the effectiveness of this mathematical programming technique for approximating complex real world inventory control problems

does garbage pricing increase the immoral disposal of household waste abstractsome empirical studies have attempted to clarify the mechanism of illegal dumping by examining the degree to which per bag pricing plays a role however previous research on the behaviour of avoiding paying a charge for waste collection has tended to neglect so called immoral disposal which is less risky than illegal dumping because there is no legal penalty in this study we define immoral disposal as the dumping of waste in a manner that is immoral but not illegal to detect the existence of immoral disposal we apply a spatial econometric approach namely an extended panel spatial durbin model to identify the actual spillover effect of garbage pricing in neighbouring municipalities on immoral disposal from the total waste a major finding of this study is that immoral disposal exists in unit based pricing two tiered pricing and fixed pricing

feed in subsidies taxation and inefficient entry we study energy markets with dirty production and lumpy entry costs of clean production renewables for intermediate entry costs markets yield inefficient production and inefficient entry a mix of three popular regulatory instruments polluter taxation feed in subsidies for renewables and consumption taxation cannot correct these market failures for larger entry costs the instruments are imperfect because they affect marginal incentives whereas entry is a lumpy fixed cost problem whenever the first best is implementable feed in subsidies and consumption taxes are redundant the second best requires feed in subsidies or consumption taxes in addition to a pollution tax and overshoots first best levels given production levels the instruments do not affect the regulator s budget

how does the choice of the gender indicator affect the analysis of gender differences in agricultural productivity evidence from uganda summary we use ols and decomposition techniques to investigate gender differences in agricultural productivity in uganda using nationally representative surveys from years 2009 2012 the analysis applies different gender dummies female head of household female plot holder and female plot manager to investigate how the variable of choice affects the calculation of the gender gap our analysis obtains different results depending on the gender variable of choice the study finds that regardless of the variable of choice the gender gap in agricultural productivity decreases or disappears when factors of production and crop choice are controlled for the conditional gender gap is about 10 and significant when using female plot manager as the gender variable while we find no conditional gender gap when using the other gender variables the use of time fixed effects and decomposition contributes evidence that the typically available gender variables are insufficient for identifying how gender and decision making of different household members play a role in productivity this finding is problematic for targeting effective interventions to increase agricultural productivity and reduce gender inequalities in agriculture finally we find that the older status of female heads holders and manager of plots child dependency ratio and limited access to adult male labor are factors decreasing productivity in female plots in uganda

noncooperative decision making in the household evidence from malawi this paper proposes a novel test of productive efficiency in the household that also allows a test of noncooperative decision making i extend the collective model chiappori 1988 1997 to allow labor choices to affect future bargaining power by raising the value of outside options even if household consumption sharing is efficient labor choices are no longer efficient using data on malawi where there is predetermined variation in land rights that determine outside options in marriage i show that individuals spend more time on agricultural labor and less time on wage labor when household land is theirs they also have lower overall income and consumption the results are inconsistent with the fully efficient collective model but consistent with a noncooperative model with limited commitment where individuals allocate their labor supply to maximize future bargaining power limited commitment can lead to inefficient allocations that reduce household welfare

s s policies for a dynamic inventory model with stochastic lead times this study analyzes a stochastic lead time inventory model under the assumptions that a replenishment orders do not cross in time and b the lead time distribution for a given order is independent of the number and sizes of outstanding orders the study extends the existing literature on the finite horizon version of the model and yields an intuitively appealing dynamic program that is nearly identical to one that would apply in a transformed model with all lead times fixed at zero hence many results that have been derived for fixed lead time models generalize easily conditions for the optimality of myopic base stock policies and for the optimality of s s policies are established for both finite and infinite planning horizons the infinite horizon model analysis is extended by adapting the fixed lead time results for the efficient computation of optimal and approximately optimal s s policies

application of the distance function to nonmarket valuation of environmental goods and services an illustrative example abstract this paper develops and implements a unique formulation of a household production model in that technology is characterized as a distance function the properties of the distance function allow for the derivation of shadow prices for the inputs and outputs associated with household production which can be applied to the problem of valuing nonmarket goods or activities the approach requires only one input to or output of household production to bear a price the derivation of shadow prices for all other household inputs outputs follows from the properties of the distance function i demonstrate the approach using data on the waste management activities of a sample of households from marietta georgia and by calculating shadow prices for the nonmarket activity of recycling

gender inequalities in ownership and control of land in africa myth and reality lack of clarity behind measurement and interpretation of statistics on gender and land leads to an inability to clearly articulate a policy response to the potential inequalities faced by women and men this article sets out to explore conceptually and empirically the levels and relative inequalities in land rights between women and men in african countries the first section of the article engages in a conceptual discussion of how to measure gendered land outcomes what ownership and control mean in different contexts and why attention to these factors is important for the development of gender and land statistics the second section of the article systematically reviews existing evidence from microlevel large sample studies to summarize recent trends in land access ownership and control by sex the third section presents new statistics from a variety of nationally representative and large scale unpublished data on gender and land in africa results provide not only a nuanced understanding of the importance of measuring land indicators for gendered development in africa and globally but also new statistics on a variety of land outcomes to aid stakeholders in the discussion of gender land inequalities

reconsideration of an advance disposal fee policy for end of life durable goods abstract this paper analyzes the optimal waste disposal policy for durable goods the existing literature does not differentiate between durable and non durable goods and concludes that the social optimum can be attained by either a disposal fee df policy or an advance disposal fee adf policy in an economy without transaction costs this study shows however that in such an economy the first best policy is not an adf policy but a df policy adoption of an adf policy results in excessive consumption and disposal compared to the social optimum in addition under an adf policy the lifetime of durable goods is shorter than the social optimum if we take transaction costs into account we must consider the second best policy an adf policy can be considered as second best in some situations since it has some transaction cost advantages over other policies an adf policy can be second best either if net disposal cost is relatively low or if repair cost is relatively high

an economic analysis of household waste management abstract this paper provides a comprehensive model of household waste management policy incorporating the possibility of waste reduction effort by the firm and the household and of illegal waste disposal by the household when household waste reduction effort is insignificant the first best optimum can be achieved using various combinations of environmental tax on the firm and waste collection charge on the household however when household waste reduction effort is significant the first best optimum is not achievable and explicit monitoring of illegal waste disposal is needed rendering a simple pigouvian tax sub optimal this paper solves for the second best optimal policy and provides some comparative statics of the optimal policy

game theoretic pricing and ordering decisions with partial lost sales in two stage supply chains abstract few papers have studied the optimal pricing and ordering with partial lost sales from a two stage game theoretic perspective this paper considers a supply chain game with a buyer and a seller through pricing and ordering models with partial lost sales we evaluate the optimal solutions for the buyer and the seller and provide insights into both the deterministic and stochastic demand models we also propose search algorithms to obtain the global optimum when convexity and concavity conditions are not satisfied