the growth potential of startups over the business cycle this paper shows that employment in cohorts of us firms is strongly influenced by aggregate conditions at the time of their entry employment fluctuations of startups are procyclical they persist into later years and cohort level employment variations are largely driven by differences in firm size rather than the number of firms an estimated general equilibrium firm dynamics model reveals that aggregate conditions at birth rather than post entry choices drive the majority of cohort level employment variation by affecting the share of startups with high growth potential in the aggregate changes in startup conditions result in large slow moving fluctuations in employment

a study on the future of unconventional oil development under different oil price scenarios a system dynamics approach abstract fluctuations in the oil global market has been a critical topic for the world economy so that analyzing and forecasting the conventional oil production rate has been examined by many researchers thoroughly however the dynamics of the market has not been studied systematically with regard to the new emerging competitors namely unconventional oil in this paper the future trend of conventional and unconventional oil production and capacity expansion rates are analyzed using system dynamics approach to do so a supply side modeling approach is utilized while main effective loops are modeled mathematically as follows technological learning and progress long and short term profitability of oil capacity expansion and production and oil proved reserve limitations the proposed model is used to analyze conventional and unconventional oil production shares up to 2025 under different oil price scenarios the results show that conventional oil production rate ranges from 79 995 to 87 044 mb day which is 75 80 percent of total oil production rate while unconventional oil production rate ranges from 19 615 to 28 584 mb day simulation results reveal that unconventional oil can gain a considerable market share in the short run although conventional oil will remain as the major source for the market in the long run

scheduling the production of several items with random demands in a single facility consider the problem of scheduling the production of several items in a single facility that can produce only one item at a time this problem occurs since it is often economic to produce several items in a single facility the objective is to reduce the long run average holding backorder and setup costs we assume that demands are random with constant expected rates we allow backorders and charge holding and backlogging costs at linear time weighted rates items are produced at continuous constant rates setup times and setup costs are item dependent constants these parameters however are independent of the order of setups a real time scheduling tool is developed in three steps first with demands replaced by their expectations we compute an optimal or near optimal target cyclic schedule next we study the problem of scheduling the facility after a single disruption perturbs the inventories the goal is to recover the target cyclic schedule at minimal excess over the average cost of the cyclic schedule we formulate this as a control problem and obtain a linear recovery policy that is optimal for a large configuration of disruptions finally we select safety stocks to minimize the long run average cost of following the target schedule with the recovery policy we show that optimal safety stocks are unique and have the property that in the long run the proportion of time that an item is in stock is the ratio of backorder to holding plus backorder cost we present an example that integrates the cyclic schedule the control policy and the safety stocks

determination of safety stocks for cyclic schedules with stochastic demands abstract this paper considers the problem of scheduling the production of multiple items each with random demand on a single facility we show how the variance in demand during lead time can be estimated and present a model for determination of safety stocks and order up to levels for a fixed cyclic sequence both with and without idle time for systems with idle time we present a control model to make the decision to produce next item in sequence or idle the facility the performance of the model is tested in a simulation study

entry regulation and business start ups evidence from mexico the authors estimate the effect on business start ups of a program that significantly speeds up firm registration procedures the program was implemented in mexico in different municipalities at different dates authors estimates suggest that new start ups increased by about 4 percent in eligible industries and the authors present evidence that this is a causal effect most of the effect is temporary concentrated in the first 10 months after implementation the effect is robust to several specifications of the benchmark control group time trends the authors find that the program was more effective in municipalities with less corruption and cheaper additional procedures

entrepreneurial tail risk implications for employment dynamics starting a new business is risky this paper asks how entrepreneurial productivity risk has changed over time in the us and how this has affected employment i estimate this risk using micro data on the size distribution of new businesses and their exit rates the paper distinguishes upside and downside risk and analyzes their effects in a tractable dynamic general equilibrium of entrepreneurship at the heart of the model is the decision of potential entrepreneurs whether to start a new business in the face of uninsurable productivity risk applied to us time series data structural estimates suggest that higher upside risk explains much of the high job creation in the late 1990s over the entire sample period time variation in risk explains 40 to 55 of the variation in employment of new businesses reduced form results show that this relationship is strongest in it related industries counterfactual simulations show that the explanatory power of a model with a single risk factor drops by 30 to 50 compared to the baseline estimates

endogenous implementation of technology gap in energy optimization models a systematic analysis within times g5 model evaluation of global diffusion potential of learning technologies and their timely specific cost development across regions is always a challenging issue for the future technology policy preparation further the process of evaluation gains interest especially by endogenous treatment of energy technologies under uncertainty in learning rates with technology gap across the regions in global regional cluster learning approach this work devised implemented and examined new methodologies on technology gaps a practical problem using two broad concepts of knowledge deficit and time lag approaches in global learning applying the floor cost approach methodology the study was executed in a multi regional technology rich and long horizon bottom up linear energy system model on the integrated markal efom system times framework global learning selects highest learning technologies in maximum uncertainty of learning rate scenario whereas any form of technology gap retards the global learning process and discourages the technologies deployment time lag notions of technology gaps prefer heavy utilization of learning technologies in developed economies for early reduction of specific cost technology gaps of any kind should be reduced among economies through the promotion and enactment of various policies by governments in order to utilize the technological resources by mass deployment to combat ongoing climate change

understanding the reductions in us corn ethanol production costs an experience curve approach the us is currently the world s largest ethanol producer an increasing percentage is used as transportation fuel but debates continue on its costs competitiveness and energy balance in this study technological development of ethanol production and resulting cost reductions are investigated by using the experience curve approach scrutinizing costs of dry grind ethanol production over the timeframe 1980 2005 cost reductions are differentiated between feedstock corn production and industrial ethanol processing corn production costs in the us have declined by 62 over 30 years down to 100 2005 tonne in 2005 while corn production volumes almost doubled since 1975 a progress ratio pr of 0 55 is calculated indicating a 45 cost decline over each doubling in cumulative production higher corn yields and increasing farm sizes are the most important drivers behind this cost decline industrial processing costs of ethanol have declined by 45 since 1983 to below 130 2005 m3 in 2005 excluding costs for corn and capital equivalent to a pr of 0 87 total ethanol production costs including capital and net corn costs have declined approximately 60 from 800 2005 m3 in the early 1980s to 300 2005 m3 in 2005 higher ethanol yields lower energy use and the replacement of beverage alcohol based production technologies have mostly contributed to this substantial cost decline in addition the average size of dry grind ethanol plants increased by 235 since 1990 for the future it is estimated that solely due to technological learning production costs of ethanol may decline 28 44 though this excludes effects of the current rising corn and fossil fuel costs it is also concluded that experience curves are a valuable tool to describe both past and potential future cost reductions in us corn based ethanol production

the economics of technical change this paper reviews the recent rapidly growing literature on technical change in the economy it concentrates on innovations and their diffusion at firm and industry level since this was the area designated as relatively weak in earlier literature surveys the review argues that the extensive empirical evidence and theoretical analysis now available presents a basic challenge to neoclassical theory after indicating some weaknesses in the neo schumpeterian literature the paper concludes by advocating an experiment with a new form of assessment by neighboring disciplines to economics itself which would take full account of the fundamental issues at stake in this modern methodenstreit c 1994 academic press inc copyright 1994 by oxford university press

cyclical schedules vs dynamic sequencing replenishment dynamics and inventory efficiency abstract this paper addresses the efficiency of fixed sequence cyclical scheduling systems relative to that of dynamically sequenced order point methods of production control the criterion for comparison is the aggregate inventory required to achieve a target fill rate taking into account the alternative replenishment dynamics arising under the respective systems a simulation analysis demonstrates that cyclical scheduling may have smaller aggregate inventory requirement when the production process is highly utilized and when this utilization is due to demand for a small number of items having large setup times

energy returns and the long run growth of global industrial society abstract the extreme interconnectedness of energy and economic systems will tend to confound any attempt to estimate the energy return on investment at anything other than the global scale here i apply a very simple model of global energy use to specify the dynamic characteristics of global scale energy returns on investment eroig this suggests that the observed long run relative growth rate of 2 5 yr 1 in global primary energy use is associated with an equilibrium return from infrastructure investments of 2 1 with returns accruing with a time constant of 40 years the analysis also attempts to show how growth leads to reductions in the supply efficiency of energy and how this decline is offset by increases in the efficiency with which industrial society can extract useful work from primary energy flows this observed preservation of the overall energy efficiency of the global energy system implicates variations in the decay decommissioning rate of infrastructure in observed long wave like variations in the relative growth rate of global primary energy use and hence eroig

environmental performance innovation and spillovers evidence from a regional namea abstract the achievement of positive environmental performance ep at national level could strongly depend on differences in regional features namely productive specialization regulation stringency and innovation capabilities of both public institutions and the private business sector we present empirical evidence for a newly released namea available for the 20 italian regions in order to demonstrate the role played by sector innovation regional spillovers and environmental policies the italian north south divide regarding industrial development and productive specialization patterns seems to affect regional ep nonetheless such a pattern presents some interesting differences revealing a more heterogeneous distribution of emissions which may reflect the role of other driving forces in particular agglomerative effects seem to play a major role and the ep of neighboring regions influences the regional internal ep this means that together with the spatial concentration of specific sectors into restricted areas there is also some convergence in the adoption of cleaner or dirtier production process techniques finally interregional technological spillovers are more important than sector internal innovation for improving ep revealing that accounting for spatial features and linking ecological economics to regional economics are crucial in understanding the key drivers of ep

zero energy homes are they economically viable whilst net zero energy homes are espoused in many policy circles and many bespoke examples have been constructed to demonstrate their technical feasibility there is a scarcity of evidence demonstrating such a standard would be economically rational particularly for large scale housing development where orientation and aspect may not always be optimal drawing on energy monitoring evidence and construction economics associated with a nearly zero energy housing estate in adelaide australia this paper explores the economic feasibility of the net zero energy home policy in warm temperate climates the results demonstrate that using economic tools and assumptions typically applied for building energy regulatory policy changes net societal economic benefits significantly outweigh costs the clear economic outcomes combined with expected health and productivity benefits from improved levels of thermal comfort should provide security to policy makers to progress home energy standards towards net zero energy performance

tortoises and hares choice among technologies of unknown merit recent work in the area of competing technologies and increasing returns has largely been concerned with the effectiveness of the market in delivering optimal outcomes the existence of inefficient market outcomes suggests that there might be a place for intervention in the technology choice process this paper develops a model of sequential choice in which the choice process is subject to centralized control the model is used to show that intervention can increase the expected present value of the technology adoption process it remains however that one technology and not necessarily the best will come to dominate the market copyright 1991 by royal economic society

ftt power a global model of the power sector with induced technological change and natural resource depletion abstract this work introduces a model of future technology transformations for the power sector ftt power a representation of global power systems based on market competition induced technological change itc and natural resource use and depletion it is the first component of a family of sectoral bottom up models of technology designed for integration into the global macroeconometric model e3mg itc occurs as a result of technological learning produced by cumulative investment and leads to highly nonlinear irreversible and path dependent technological transitions the model uses a dynamic coupled set of logistic differential equations as opposed to traditional bottom up energy models based on systems optimisation such differential equations offer an appropriate treatment of the times and structure of change involved in sectoral technology transformations as well as a much reduced computational load resource use and depletion are represented by local cost supply curves which give rise to different regional energy landscapes the model is explored for a single global region using two simple scenarios a baseline and a mitigation case where the price of carbon is gradually increased while a constant price of carbon leads to a stagnant system mitigation produces successive technology transitions leading towards the gradual decarbonisation of the global power sector

the demand for environmental quality in driving transitions to low polluting energy sources the purpose of this paper is to understand the long run demand for energy related environmental quality its influence on legislation and on transitions to low polluting energy sources it starts by presenting a simple framework of the relationship between the demand for and supply of environmental quality environmental legislation and energy this forms the structure for presenting a series of episodes in british history where a demand for improvements in energy related environmental quality existed this analysis proposes that markets can drive transitions to low polluting energy sources in specific economic conditions however most probably governments will need to push them and this cannot be expected without strong and sustained demand for environmental improvements yet while demand is a prerequisite it is not enough it must also be spearheaded by strong creative and sustained pressure groups i e powerful lobbying and the weakening of the counter lobby to introduce legislation to enforce it and to avoid it being over turned by future governments

technological learning in energy environment economy modelling a survey abstract this paper aims at providing an overview and a critical analysis of the technological learning concept and its incorporation in energy environment economy models a special emphasis is put on surveying and discussing through the so called learning curve both studies estimating learning rates in the energy field and studies incorporating endogenous technological learning in bottom up and top down models the survey of learning rate estimations gives special attention to interpreting and explaining the sources of variability of estimated rates which is shown to be mainly inherent in r d expenditures the problem of omitted variable bias the endogeneity relationship and the role of spillovers large scale models survey show that despite some methodological and computational complexity related to the non linearity and the non convexity associated with the learning curve incorporation results of the numerous modelling experiments give several new insights with regard to the analysis of the prospects of specific technological options and their cost decrease potential bottom up models and with regard to the analysis of strategic considerations especially inherent in the innovation and energy diffusion process in particular the energy sector s endogenous responses to environment policy instruments top down models

the role of startups for local labor markets there are substantial differences in startup activity across us local labor markets we study the causes and consequences of these differences startup productivity shocks are found to drive much of these cross city differences in startup activity examples of such shocks include breakthroughs in biotech that spurred startup formation in san diego and philadelphia overall these shocks explain half of the forecast error variance of startup job creation accounting for 40 of population growth and long run changes in employment shocks to barriers to firm entry have economy wide effects similar to those of startup productivity shocks but operate largely through the number of startups rather than their size we use a novel spatial panel vector autoregression identifying shocks using shift share external instruments

a global and local endogenous experience curve model for projecting future uptake and cost of electricity generation technologies abstract a global and local learning model gallm has been developed to project the cost and global uptake of different electricity generation technologies to the year 2050 this model features three regions endogenous technological learning within and across those regions various government policies to facilitate technological learning and a penalty constraint which is used to mimic the effect market forces play on the capital cost of electricity generation technologies this constraint has been added as market forces have been a strong factor in technology pricing in recent years global regional and component experience curves have been developed for some technologies the model with the inclusion of these features projects a diverse range of technologies contributing to global electricity generation under a carbon price scenario the penalty constraint leads to gradual and continual installations of technologies and because the constraint provides a disincentive to install too much of a technology it reduces the impact of uncertainty in the learning rate alternative forms of the penalty constraint were tested for their suitability it was found that with a zero and lower cost version of the constraint photovoltaics are installed in a boom and bust cycle which is not supported by past experience when the constraint is set at a high level there are fewer installations

prospects for expanded utilization of biogas in germany the prospects for expanded utilization of biogas systems in german was analysed by identifying the operational and policy factors affecting the complete chain of processes from implementation process for biogas plants through to biogas production and utilization it was found that the renewable energies act eeg and energy tax reliefs provide bases for the support of expanded utilization upgrading of biogas to natural gas quality for utilization in the transportation sector was arguably the most promising technology that could support rapid utilization expansion sustainable deployment of biogas systems in light of the unstable feedstock prices and availability and the need for subsidy free operation in the long term requires enhancement of feedstock flexibility and quality characteristics to maximise gas yield and optimisation of the anaerobic digestion process management assessment of energy balance and potential environmental impacts of the integrated process chain provides a holistic assessment of sustainability the results also support the development and foster of policies and framework for development of biogas as environmentally friendly energy resource among a mix of renewable energy sources hence compete favourably with fossil fuels to enhance the prospects for expanded utilization

historical energy price shocks and their changing effects on the economy abstract the purpose of this paper is to identify the changes in the impact of energy shocks on economic activity with an interest in assessing if an economy s vulnerability and resilience to shocks improved with economic development using data on the united kingdom over the last three hundred years the paper identifies supply aggregate demand and residual shocks to energy prices and estimates their changing influence on energy prices and gdp the results suggest that the impacts of supply shocks rose with its increasing dependence on coal and declined with its partial transition to oil however the transition from exporting coal to importing oil increased the negative impacts of demand shocks more generally the results indicate that improvements in vulnerability and resilience to shocks did not progress systematically as the economy developed instead the changes in impacts depended greatly on the circumstances related to the demand for and supply of energy sources if these experiences are transferable to future markets a transition to a diversified mix of renewable energy is likely to reduce vulnerability and increase resilience to energy price shocks

the diffusion of clean technologies a review with suggestions for future diffusion analysis abstract this article gives an overview of the literature on clean technology diffusion followed by suggestions for future analysis findings from diffusion analysis are presented in the form of 10 stylised facts helping the reader to see the forest for the trees the overall conclusion is that the diffusion of clean technology same as the diffusion of normal innovations is governed by endogenous mechanism epidemic learning and learning economies and by exogenous mechanisms policy is important for clean technology diffusion but other factors are important too the characteristics of the clean technology absorptive capacities of potential adopters and the age structure of capital it is often overlooked that companies have a choice they can choose between an end of pipe solution a process change adaptation and a change of process substitution this means that the diffusion and evolution of one clean technology will be at the expense of the diffusion of another clean technology something overlooked in studies on clean technology diffusion further research is needed on the influence of public policy on clean technology choice expectations about learning economies and prices adjustment costs network externalities and complementary innovations on clean technology adoption choices

the ambiguity of innovation drivers the adoption of information and communication technologies by public water utilities abstract information and communication technologies have the potential to increase productivity improving efficiency and eventually raising the quality of water services although this potential is recognized great variation exists in the way water utilities adopt information and communication technologies based on literature review and empirical data drawn from the three case studies a municipality in greece an airport in italy and a water utility in the netherlands developed under the eu funded waternomics project the paper highlights how environmental organizational and individual factors explain technology adoption the paper pays particular attention to the idiosyncrasies of the water services sector which influence this process these include include the social and conomic importance of water supply the monopolistic nature of the sector and increased commercialization of public water utilities our cases suggest that drivers of technology adoption appear to be somewhat ambiguous in the water services sector in that they impact adoption in diverse locations differently our cases also suggest is that the prioritization of the factors that determine adoption are dynamic and change over time

environmental efficiency and labour productivity trade off or joint dynamics a theoretical investigation and empirical evidence from italy using namea in this paper we test an adapted ekc hypothesis to verify the relationship between environmental efficiency namely emissions per unit of value added and labour productivity value added per employee we exploit namea data on italy for 29 sector branches and 6 categories of air emissions for the period 1991 2001 we employ data on capital stock and trade openness to test the robustness of our results on the basis of the theoretical and empirical analyses focusing on innovation firm performances and environmental externalities we would expect a positive correlation between environmental efficiency and labour productivity a negative correlation between the emissions intensity of value added and labour productivity which departs from the conventional mainstream view the hypothesis tested is a critical one within the longstanding debate on the potential trade off or complementarity between environmental preservation and economic performance which is strictly associated with the role of technological innovation we find that for most air emission categories there is a positive relationship between labour productivity and environmental efficiency labour productivity dynamics then seem to be complementary to a decreasing emissions intensity in the production process taking a disaggregate sector perspective we show that the macro aggregate evidence is driven by sector dynamics in a non homogenous way across pollutants services tend always to show a complementary relationship while industry seems to be associated with inverted u shape dynamics for greenhouse gases and nitrogen oxides this is in line with our expectations in any case ekc shapes appear to drive such productivity links towards complementarity the extent to which this evidence derives from endogenous market forces industrial and structural change and policy effects is discussed by taking an evolutionary perspective to innovation and by referring to impure public goods arguments

buying greenhouse insurance the economic costs of carbon dioxide emission limits in recent years a growing concern that the increasing accumulation of greenhouse gases will lead to undesirable changes in global climate has resulted in a number of proposals both in the united states and internationally to set physical targets for reducing greenhouse gas emissions but what will these proposals cost based on the authors earlier ground breaking work buying greenhouse insurance outlines a way to think about greenhouse effect decisions under uncertainty it describes an insightful model for determining the economic costs of limiting carbon dioxide emissions produced by burning fossil fuels and provides a solid analytical base for rethinking public policy on the farreaching issue of global warming manne and richels present region by region estimates of the costs that would underlie an international agreement using a computer model known as global 2100 they analyze the economic impacts of limiting c02 emissions under alternative supply and conservation scenarios the results clearly indicate that a reduction in emissions is not the sole policy response to potential climate change following a summary of the greenhouse effect its likely causes and possible consequences manne and richels take up issues that concern the public at large they provide an overview of global 2100 look at how the u s energy sector is likely to evolve under businessas usual conditions and under carbon constraints and describe the concept of greenhouse insurance they consider possible global agreements including an estimate of benefits that might result from trading in an international market in emission rights they conclude with a technical description directed toward modeling specialists alan manne is professor of operations research at stanford university richard richels is director of the energy analysis and planning department at the electric power research institute

the impact of learning by doing on the timing and costs of co2 abatement abstract a particular ceiling on atmospheric co 2 concentrations can be maintained through a variety of emission pathways over the past decade there has been considerable debate over the characteristics of a least cost pathway some have suggested that a gradual departure from the emissions baseline will be the most cost effective because it reduces the pressure for premature retirement of the existing capital stock and it provides valuable time to develop low cost low carbon emitting substitutes others counter that a major flaw in analyses that support this line of reasoning is that they ignore learning by doing lbd in this paper we examine the impact of lbd on the timing and costs of emissions abatement with regard to timing we find that including learning by doing does not significantly alter the conclusions of previous studies that treated technology cost as exogenous the analysis supports the earlier conclusion that for a wide range of stabilization ceilings a gradual transition away from the no policy emissions baseline is preferable to one that requires substantial near term reductions we find that the major impact of including learning by doing is on the costs of emission abatement depending upon the sensitivity of costs to cumulative experience lbd can substantially reduce the overall costs of emissions abatement

improving the economics of building energy code change a review of the inputs and assumptions of economic models abstract building energy code change in australia and many other developed nations is subject to standardised economic tests with a net present value calculation at the heart of the economic analysis although many nations have introduced minimum energy efficiency standards for residential and commercial buildings increases in stringency have been hindered by limitations to the range of private and societal impacts typically incorporated in regulatory impact assessments given the policy move towards net zero energy homes a more comprehensive set of inputs and robust assumptions are needed to support further regulatory change yet the literature provides substantial evidence of many private and societal costs and benefits not commonly incorporated into the economic assessments that underpin regulatory change drawing on a case study of australian and uk residential regulatory change assessments this paper highlights limitations to the range of inputs and assumptions currently incorporated within the economic arguments applied during residential energy code change processes and presents a more comprehensive economic argument that could support further stringency improvements

assessing the incidence and efficiency of a prominent place based policy abstract this paper empirically assesses the incidence and efficiency of round i of the federal urban empowerment zone ez program using confidential microdata from the decennial census and the longitudinal business database using rejected and future applicants to the ez program as controls we find that ez designation substantially increased employment in zone neighborhoods and generated wage increases for local workers without corresponding increases in population or the local cost of living the results suggest the efficiency costs of first round ezs were relatively modest jel h26 h77 j31 r23 r58

energy environment policy modeling of endogenous technological change with personal vehicles combining top down and bottom up methods abstract the transportation sector offers substantial potential for greenhouse gas ghg emission abatement but widely divergent cost estimates complicate policy making energy economy policy modelers apply top down and bottom up cost definitions and different assumptions about future technologies and the preferences of firms and households our hybrid energy economy policy model is technology rich like a bottom up model but has empirically estimated behavioral parameters for risk and technology preferences like a top down model unlike typical top down models however it simulates technological change endogenously with functions that relate the financial costs of technologies to cumulative production and adjust technology preferences as market shares change we apply it to the choice of personal vehicles to indicate first the effect on cost estimates of divergent cost definitions and second the possible response to policies that require a minimum market share for low emission vehicles

lot sizes in a capacity constrained facility a simulation study of stationary stochastic demand abstract this paper considers the scheduling of several different items on a single machine in literature known as the economic lot scheduling problem elsp one of the characteristics of this problem is that the demand rate is deterministic and constant however in a practical situation demand usually varies in this paper we examine if a deterministic model can be used if demand is stationary stochastic a dynamic programming approach from bomberger manage sci 12 11 1966 778 and a heuristic method from segerstedt int j production econom 59 1 3 1999 469 are used to calculate lot sizes for four items the production of these items is simulated with different variations in demand rates our conclusion is that a deterministic model of this kind can be used in a practical situation where the demand rate is stationary stochastic but the models must be complemented by a decision rule which item to produce and when to produce it in our tests the heuristic method and the dynamic programming approach perform rather similarly with respect to costs and inventory levels but the dynamic programming approach results in more backorders when there is small variation in demand rates this study indicates that the model used for determination of lot sizes is of less importance than the decision rule used for identification of the item to produce and when to produce it

socio technical barriers to the use of energy efficient timber drying technology in new zealand abstract this study of industrial energy behaviours identifies barriers to the use of energy efficient drying technology in the new zealand timber industry and explores these barriers through the energy cultures lens vented kiln dryers were preferred by larger firms and heat pump kiln dryers were used by smaller firms although few firms could specify all their costs we found no significant differences in the average operating costs drying costs or commercial success of the larger and smaller firms we found that socio technical barriers create energy cultures at the level of both the firm and the sector supporting the dominance of vented kiln dryers the prevailing technologies practices and norms at the sector level strongly support vented kilns the status quo being embedded in the socio technical context hindering technological learning improved energy efficiency and innovation influential stakeholders in the industry were thus part of and locked into the industry wide energy culture and were not in a position to effect change we conclude that actors external to the prevailing industry energy culture need to leverage change in the industry norms practices and or technologies in order to reap the advantages of energy efficient drying technology assist its continued evolution and avoid the risks of path dependency

on the global economic potentials and marginal costs of non renewable resources and the price of energy commodities a model is presented in this work for simulating endogenously the evolution of the marginal costs of production of energy carriers from non renewable resources their consumption depletion pathways and timescales such marginal costs can be used to simulate the long term average price formation of energy commodities drawing on previous work where a global database of energy resource economic potentials was constructed this work uses cost distributions of non renewable resources in order to evaluate global flows of energy commodities a mathematical framework is given to calculate endogenous flows of energy resources given an exogenous commodity price path this framework can be used in reverse in order to calculate an endogenous marginal cost of production of energy carriers given an exogenous carrier demand using rigid price inelastic assumptions independent of the economy these two approaches generate limiting scenarios that depict extreme use of natural resources this is useful to characterise the current state and possible uses of remaining non renewable resources such as fossil fuels and natural uranium the theory is however designed for use within economic or technology models that allow technology substitutions in this work it is implemented in the global power sector model ftt power policy implications are given

diffusion paths for micro cogeneration using hydrogen in the netherlands we estimate the diffusion of micro cogeneration systems micogen using hydrogen produced from natural gas in the netherlands for the 2000 2050 period on the basis of economical factors the diffusion is important for the transition to a hydrogen economy based on renewables with natural gas paving the way for hydrogen from renewables for three scenarios full diffusion takes place in the period 2020 2050 the most important factors behind the diffusion are 1 growing energy demand resulting in lower hydrogen costs and higher energy costs in the reference case and 2 lower costs of micogen stemming from learning economies the model is advanced by considering all costs components for heterogeneous users which have been calculated for the entire diffusion period it is the first threshold diffusion model that is being applied to the diffusion of technological clusters involving new or adapted infrastructures 2007 elsevier ltd all rights reserved

economic order quantities in production from harris to economic lot scheduling problems abstract this article provides a short historical overview from harris and his economic order quantity eoq formula to the economic lot scheduling problem elsp the aim is to describe the development of the elsp field from the eoq formula to the advanced methods of today in a manner that suits master and graduate students the article shows the complexities difficulties and possibilities of scheduling and producing several different items in a single production facility with constrained capacity the items have different demand cost operation time and set up time set up time consumes capacity and makes the scheduling more complicated idle time makes the scheduling easier but is bad from a practical point of view since it creates unnecessary costs due to low utilisation of the facility a heuristic solution method is used on a small numerical example to illustrate different solution approaches the solution method creates a detailed schedule and estimates the correct set up and inventory holding cost even if the facility works close to its capacity

dynamics of energy technologies and global change technological choices largely determine the long term characteristics of industrial society including impacts on the natural environment however the treatment of technology in existing models that are used to project economic and environmental futures remains highly stylized based on work over two decades at iiasa we present a useful typology for technology analysis and discuss methods that can be used to analyze the impact of technological changes on the global environment especially global warming our focus is energy technologies the main source of many atmospheric environmental problems we show that much improved treatment of technology is possible with a combination of historical analysis and new modeling techniques in the historical record we identify characteristic l such network e ects yield high barriers to entry even for superior competitors these simple observations allow three improvements to modeling of technological change and its consequences for global environmental change one is that the replacement of long lived infrastructures over time has also replaced the fuels that power the economy to yield progressively more energy per unit of carbon pollution from coal to oil to gas such replacement has d they also include endogenous generation of s we show that doing so can yield projections with lessened environmental impacts without necessarily incurring negative e ect on the economy arriving on that path by the year 2100 depends on intervening actions such as incentives to promote greater diversity in technology and lower barriers to entry for new infrastructures that could accelerate historical trends of decarbonization 1999 elsevier science ltd all rights reserved

from government to market and from producer to consumer transition of policy mix towards clean mobility in china abstract this paper proposes a new typology that classifies innovation policy instruments into two dimensions government selection versus market selection and producer orientation versus consumer orientation such a typology articulates the importance of consumer behavior in the policy design for a transition and the relevance for the market to select target subjects of policy during the deployment stage of clean technology innovation we apply this typology to policy instruments of china s new energy vehicle nev industry between 1991 and 2015 in order to explain the industry s rapid growth the focus of china s policy mix has transited from government selection to market selection and from producer orientation to consumer orientation other than the new typology this paper traces the entire history of policy transition within china s nev industry and finds the transition to be a result of policy learning thus contributing to future empirical studies of this industry