China implemented its Action Plan of Air Pollution Prevention and Control(APAPPC)in 2013 as a major step in national air-quality management.This study treated the APAPPC as a quasi-experiment,drawing on the Grossman a...China implemented its Action Plan of Air Pollution Prevention and Control(APAPPC)in 2013 as a major step in national air-quality management.This study treated the APAPPC as a quasi-experiment,drawing on the Grossman and Cropper models,to examine how air pollution affected individual health capital and medical service demand.Using panel data from the China Health and Retirement Longitudinal Study for 2011,2013,2015,and 2018,the analysis applied a Heckman two-stage model and difference-in-differences estimation to identify the policy's effects on medical expenditure.The results showed that the APAPPC significantly reduced annual health spending,with stronger effects among women,older adults,and rural residents.The mechanism analysis indicated that the reduction in respiratory diseases played a key role.This study provides evidence that supports further airpollution control in China and offers useful insights for other developing countries.展开更多
With the development of sharded blockchains,high cross-shard rates and load imbalance have emerged as major challenges.Account partitioning based on hashing and real-time load faces the issue of high cross-shard rates...With the development of sharded blockchains,high cross-shard rates and load imbalance have emerged as major challenges.Account partitioning based on hashing and real-time load faces the issue of high cross-shard rates.Account partitioning based on historical transaction graphs is effective in reducing cross-shard rates but suffers from load imbalance and limited adaptability to dynamic workloads.Meanwhile,because of the coupling between consensus and execution,a target shard must receive both the partitioned transactions and the partitioned accounts before initiating consensus and execution.However,we observe that transaction partitioning and subsequent consensus do not require actual account data but only need to determine the relative partition order between shards.Therefore,we propose a novel sharded blockchain,called HATLedger,based on Hybrid Account and Transaction partitioning.First,HATLedger proposes building a future transaction graph to detect upcoming hotspot accounts and making more precise account partitioning to reduce transaction cross-shard rates.In the event of an impending overload,the source shard employs simulated partition transactions to specify the partition order across multiple target shards,thereby rapidly partitioning the pending transactions.The target shards can reach consensus on received transactions without waiting for account data.The source shard subsequently sends the account data to the corresponding target shards in the order specified by the previously simulated partition transactions.Based on real transaction history from Ethereum,we conducted extensive sharding scalability experiments.By maintaining low cross-shard rates and a relatively balanced load distribution,HATLedger achieves throughput improvements of 2.2x,1.9x,and 1.8x over SharPer,Shard Scheduler,and TxAllo,respectively,significantly enhancing efficiency and scalability.展开更多
BACKGROUND Drug utilization research has an important role in assisting the healthcare administration to know,compute,and refine the prescription whose principal objective is to enable the rational use of drugs.Resear...BACKGROUND Drug utilization research has an important role in assisting the healthcare administration to know,compute,and refine the prescription whose principal objective is to enable the rational use of drugs.Research in developing nations relating to the cost of treatment is scarce when compared with developed countries.Thus,the drug utilization research studies from developing nations are most needed,and their number has been growing.AIM To evaluate patterns of utilization of antipsychotic drugs and direct medical cost analysis in patients newly diagnosed with schizophrenia.METHODS The present study was observational in type and based on a retrospective cohort to evaluate patterns of utilization of antipsychotic drugs using World Health Organization(WHO)core prescribing indicators and anatomical therapeutic chemical/defined daily dose indicators.We also calculated direct medical costs for a period of 6 months.RESULTS This study has found that atypical antipsychotics are the mainstay of treatment for schizophrenia in every age group and subcategories of schizophrenia.The evaluation based on WHO prescribing indicators showed a low average number of drugs per prescription and low prescribing frequency of antipsychotics from the National List of Essential Medicines 2015 and the WHO Essential Medicines List 2019.The total mean drug cost of our study was 1396 Indian rupees.The total mean cost due to the investigation in our study was 1017.34 Indian rupees.Therefore,the total mean direct medical cost incurred on patients in our study was 4337.28 Indian rupees.CONCLUSION The information from the present study can be used for reviewing and updating treatment policy at the institutional level.展开更多
The new RE 6 EL from KARL MAYER brings a breath of fresh air to raschel fabric production.Nowadays textile companies increasingly need to produce small production runs and respond to market changes with instantaneous ...The new RE 6 EL from KARL MAYER brings a breath of fresh air to raschel fabric production.Nowadays textile companies increasingly need to produce small production runs and respond to market changes with instantaneous pattern changes in order to operate profitably–meaning they require machines that offer maximum flexibility,reliability and cost efficiency.KARL MAYER understands the challenges of the market and is launching its new RE 6 EL.The Raschel machine offers the core strengths of the classic RSE 6 EL and essentially the same performance parameters,but has been further cost-optimised largely due to local production advantages.This makes the newcomer an efficiency champion in production,especially when it comes to frequent pattern changes.展开更多
With the introduction of the“dual carbon”goal and the continuous promotion of low-carbon development,the integrated energy system(IES)has gradually become an effective way to save energy and reduce emissions.This st...With the introduction of the“dual carbon”goal and the continuous promotion of low-carbon development,the integrated energy system(IES)has gradually become an effective way to save energy and reduce emissions.This study proposes a low-carbon economic optimization scheduling model for an IES that considers carbon trading costs.With the goal of minimizing the total operating cost of the IES and considering the transferable and curtailable characteristics of the electric and thermal flexible loads,an optimal scheduling model of the IES that considers the cost of carbon trading and flexible loads on the user side was established.The role of flexible loads in improving the economy of an energy system was investigated using examples,and the rationality and effectiveness of the study were verified through a comparative analysis of different scenarios.The results showed that the total cost of the system in different scenarios was reduced by 18.04%,9.1%,3.35%,and 7.03%,respectively,whereas the total carbon emissions of the system were reduced by 65.28%,20.63%,3.85%,and 18.03%,respectively,when the carbon trading cost and demand-side flexible electric and thermal load responses were considered simultaneously.Flexible electrical and thermal loads did not have the same impact on the system performance.In the analyzed case,the total cost and carbon emissions of the system when only the flexible electrical load response was considered were lower than those when only the flexible thermal load response was taken into account.Photovoltaics have an excess of carbon trading credits and can profit from selling them,whereas other devices have an excess of carbon trading and need to buy carbon credits.展开更多
We study the dividend optimization problem for an insurance company under the consideration of internal competition between different units inside company and transaction costs when dividends occur. The management of ...We study the dividend optimization problem for an insurance company under the consideration of internal competition between different units inside company and transaction costs when dividends occur. The management of the company controls the reinsurance rate, the timing and the amount of dividends paid out to maximize the expected total dividends paid out to the shareholders until ruin time. By solving the corresponding quasi-variational inequality, we obtain the optimal return function and the optimal strategy.展开更多
The purpose of present work is to examine the financial problem of finding the universal reservation prices of a European call option written on exchange rate when there is proportional transaction costs of trading fo...The purpose of present work is to examine the financial problem of finding the universal reservation prices of a European call option written on exchange rate when there is proportional transaction costs of trading foreign currency in the market. An approach is suggested to compute the reservation bid-ask price of foreign currency call option based on maximizing the investor＇s expected utility. Option prices are determined from the investor＇s basic portfolio selection problem, without the need to solve a more complex optimization problem involving the insertion of the option payoffs into the terminal value function. Option prices are computed numerically in a Markov chain approximation for the case of exponential utility. Numerical results show that the option price bounds are almost independent of the alternative risk aversion parameter, but the bounds of NT region becomes narrower and the range of values of the initial holding for which the fair price lies within the bid-ask spread is shifted to a lower value when the risk aversion parameter increases.展开更多
Global environmental meeting, legislating a reduction in the emission of greenhouse gases for planet earth, is what mankind now hopes for, having realized the enormous dangers in the process of climate change. Global ...Global environmental meeting, legislating a reduction in the emission of greenhouse gases for planet earth, is what mankind now hopes for, having realized the enormous dangers in the process of climate change. Global warming is no longer denied by the so-called cornucopians （e.g. Lomberg）, but global policy-making originating in reunions of 190 governments or more stumble on collective action difficulties, spelled out in game theory. Paris will not succeed where Copenhagen failed, namely to arrive at a binding and enforceable global environment policy that will be implemented before it is too late. Instead, there will be massive transaction costs from negotiating and re-negotiating, endless voting, the making of promises exante and reneging ex post, as well as the futile attempts at any enforcement action, given state sovereignty. Mankind will have to learn how to cope with the outcomes of global warming, as resilience is the only hope.展开更多
This paper concerns optimal investment problem with proportional transaction costs and finite time horizon based on exponential utility function. Using a partial differential equation approach, we reveal that the prob...This paper concerns optimal investment problem with proportional transaction costs and finite time horizon based on exponential utility function. Using a partial differential equation approach, we reveal that the problem is equivalent to a parabolic double obstacle problem involving two free boundaries that correspond to the optimal buying and selling policies. Numerical examples are obtained by the binomial method.展开更多
In this paper, the discrete mean-variance model is considered for portfolio selection under concave transaction costs. By using the Cholesky decomposition technique, the convariance matrix to obtain a separable mixed ...In this paper, the discrete mean-variance model is considered for portfolio selection under concave transaction costs. By using the Cholesky decomposition technique, the convariance matrix to obtain a separable mixed integer nonlinear optimization problem is decomposed. A brand-and-bound algorithm based on Lagrangian relaxation is then proposed. Computational results are reported for test problems with the data randomly generated and those from the US stock market.展开更多
This study examines the transaction costs of collaborative watershed management in the Cuyahoga River Area of Concern(AOC)—one of the 43 geographic areas designated by the U.S.and Canada Great Lakes Water Quality Agr...This study examines the transaction costs of collaborative watershed management in the Cuyahoga River Area of Concern(AOC)—one of the 43 geographic areas designated by the U.S.and Canada Great Lakes Water Quality Agreement(GLWQA),where significant impairment of beneficial uses has occurred as a result of human activities.The Cuyahoga River is located in Northeast Ohio,the U.S.and flows through the City of Cleveland before draining into Lake Erie—one of the five Great Lakes of North America.The watershed is degraded due to municipal and agricultural discharges,streambank erosion,and contamination from urban and industrial sources.This research explores how a diverse group of stakeholders convened under the Cuyahoga River AOC Advisory Committee to share information,coordinate activities,agree on activities that restore beneficial uses,and support strategic management actions.In this study,23 semi-structured interviews with members of the advisory committee were conducted between January 28,2020 and April 20,2020,with follow-up emails and phone calls as needed to corroborate information.A review of research articles and government documents supported the interviews,including United States Environmental Protection Agency(U.S.EPA)and Ohio Environment Production Agency(OEPA)reports on the GLWQA and Cuyahoga River Remedial Action Plans.A third source of data is from direct participant observation at quarterly meetings of the advisory committee during 2017–2020,binational AOC conferences in 2017 and 2019,and other professional events geared towards restoring the Cuyahoga River AOC in 2016–2020.Results of this study include a set of recommendations to help guide group structure and decision-making processes,including(1)employing best available technology to organize AOC events and disseminate information;(2)supporting new members with an orientation and/or mentor to clearly define formal and informal committee rules;(3)assuring equal access to detailed information on management action plans with a real time dashboard;(4)updating voting procedures and the prioritization of management actions;and(5)better incorporating underrepresented local communities and highlevel decision makers from municipalities,government agencies,and nongovernmental organizations located within the Cuyahoga River AOC.Results help to explain the collaborative process within the advisory committee and measure the institutional performance of the advisory committee in terms of efficiency,equitability,accountability,and adaptability.展开更多
To some two\|period economies with countable infinite state spaces, the existence of expectation equilibrium of real asset economies with transaction costs is given. This work extends the researches of Zame in 1993.
This paper presents an empirical analysis of the effect that participation in an agricultural cooperative has on the transaction costs and net income of apple- growing farmers in Shandong province. Compared with indep...This paper presents an empirical analysis of the effect that participation in an agricultural cooperative has on the transaction costs and net income of apple- growing farmers in Shandong province. Compared with independent farming, agricultural cooperatives reduce transaction costs by 48 yuan/mu and increase farmers＇ net income by 321 yuan/mu. Other factors found to influence transaction costs and farmers＇net income were farmer＇s gender, educational attainment, farm size, the availability of market information, distance to market, and level of government support. Independent farmers＂ most common explanations for not participating in agricultural cooperatives were that doing so would not reduce transaction costs significantly and that the cooperatives would impede the autonomy of their decision-making.展开更多
Thucydides asserts that the occupation of Decelea by the Spartans in 413 BC made the grain supply for Athens costly by forcing the transport from land onto the sea.This calls into question the well-established consens...Thucydides asserts that the occupation of Decelea by the Spartans in 413 BC made the grain supply for Athens costly by forcing the transport from land onto the sea.This calls into question the well-established consensus that sea transport was far cheaper than land transport.This paper contends that the cost of protecting supply lines-specifically the expenses associated with the warships which escorted the supply ships-rendered the grain transported on the new route exceptionally costly.In this paper,the benefits and drawbacks of a maritime economy,including transaction costs,trade dependencies,and the capabilities of warships and supply ships are discussed.展开更多
We present a parallel algorithm that computes the ask and bid prices of an American option when proportional transaction costs apply to trading in the underlying asset. The algorithm computes the prices on recombining...We present a parallel algorithm that computes the ask and bid prices of an American option when proportional transaction costs apply to trading in the underlying asset. The algorithm computes the prices on recombining binomial trees, and is designed for modern multi-core processors. Although parallel option pricing has been well studied, none of the existing approaches takes transaction costs into consideration. The algorithm that we propose partitions a binomial tree into blocks. In any round of computation a block is further partitioned into regions which are assigned to distinct processors. To minimise load imbalance the assignment of nodes to processors is dynamically adjusted before each new round starts. Synchronisation is required both within a round and between two successive rounds. The parallel speedup of the algorithm is proportional to the number of processors used. The parallel algorithm was implemented in C/C++ via POSIX Threads, and was tested on a machine with 8 processors. In the pricing of an American put option, the parallel speedup against an efficient sequential implementation was 5.26 using 8 processors and 1500 time steps, achieving a parallel efficiency of 65.75%.展开更多
The economic regionalization practice led by China local governments has gradually evolved into chaos. Local governments compete to declare for higher-leveled and large-scaled economic regions to obtain more economic ...The economic regionalization practice led by China local governments has gradually evolved into chaos. Local governments compete to declare for higher-leveled and large-scaled economic regions to obtain more economic resources and policy support in the way of policy game. The author argues that the regionalization chaos is attributed to the reason that the present theoretical support for economic regionalization overemphasizes the economic growth brought about by the economic regionalization but ignores the effect of transaction cost, which leads to constraint loss on the economic regionalization theory analysis framework. Then, the introduction of economic regionalization analysis framework based on the conflicts between scale expansion and transaction costs would establish equilibrium conditions to set up a moderate scale development for economic regions. The author hopes that the acceptance of this framework into the economic regionalization decision-making system would give guidance for making more appropriate regionalization decisions.展开更多
The Bermudan option pricing problem with variable transaction costs is considered for a risky asset whose price process is derived under the information-based model. The price is formulated as the value function of an...The Bermudan option pricing problem with variable transaction costs is considered for a risky asset whose price process is derived under the information-based model. The price is formulated as the value function of an optimal stopping problem, which is the value function of a stochastic control problem given by a non-linear second order partial differential equation. The theory of viscosity solutions is applied to solve the stochastic control problem such that the value function is also the solution of the corresponding Bellman equation. Under some regularity assumptions, the existence and uniqueness of the solution of the pricing equation are derived by the application of the Perron method and Banach Fixed Point theorem.展开更多
Foreign-funded overseas industrial parks(OIPs)are crucial for attracting foreign investment and promoting globalization in developing countries.However,large-scale land acquisition for these parks generates conflicts ...Foreign-funded overseas industrial parks(OIPs)are crucial for attracting foreign investment and promoting globalization in developing countries.However,large-scale land acquisition for these parks generates conflicts between developers and local stakeholders,increasing development costs.A qualitative multicase study was conducted in this study to analyze the land transaction trajectories of China's OIPs.Four OIPs were selected to reveal the underlying mechanisms from the perspectives of institutional arrangements,governance mechanisms,and enterprise heterogeneity.The findings indicate that in host countries with insufficient institutional development,local governments are more inclined to directly engage in OIP land acquisition.High-level intergovernmental mechanisms facilitate land acquisition processes,although their efficacy depends largely on administrative power allocation across parks in host countries.The results also indicate that enterprise characteristics significantly influence land acquisition,where microscale private enterprises lacking political connections often employ low-cost,bottom-up strategies by leveraging international experience.In summary,policy-makers in developing countries should prioritize enhancing OIP governance to mitigate transaction costs,promote diversified land supply,and optimize land allocation.By depicting China's OIP land acquisition processes,this study deepens the academic understanding of OIP governance in developing countries and related international land transactions,offering practical OIP management insights for governments in both host and parent countries.展开更多
基金Natural Science Foundation of Hubei Province(No.2025AFC041).
文摘China implemented its Action Plan of Air Pollution Prevention and Control(APAPPC)in 2013 as a major step in national air-quality management.This study treated the APAPPC as a quasi-experiment,drawing on the Grossman and Cropper models,to examine how air pollution affected individual health capital and medical service demand.Using panel data from the China Health and Retirement Longitudinal Study for 2011,2013,2015,and 2018,the analysis applied a Heckman two-stage model and difference-in-differences estimation to identify the policy's effects on medical expenditure.The results showed that the APAPPC significantly reduced annual health spending,with stronger effects among women,older adults,and rural residents.The mechanism analysis indicated that the reduction in respiratory diseases played a key role.This study provides evidence that supports further airpollution control in China and offers useful insights for other developing countries.
基金funded by the National Key Research and Development Program of China(Grant No.2024YFE0209000)the NSFC(Grant No.U23B2019)。
文摘With the development of sharded blockchains,high cross-shard rates and load imbalance have emerged as major challenges.Account partitioning based on hashing and real-time load faces the issue of high cross-shard rates.Account partitioning based on historical transaction graphs is effective in reducing cross-shard rates but suffers from load imbalance and limited adaptability to dynamic workloads.Meanwhile,because of the coupling between consensus and execution,a target shard must receive both the partitioned transactions and the partitioned accounts before initiating consensus and execution.However,we observe that transaction partitioning and subsequent consensus do not require actual account data but only need to determine the relative partition order between shards.Therefore,we propose a novel sharded blockchain,called HATLedger,based on Hybrid Account and Transaction partitioning.First,HATLedger proposes building a future transaction graph to detect upcoming hotspot accounts and making more precise account partitioning to reduce transaction cross-shard rates.In the event of an impending overload,the source shard employs simulated partition transactions to specify the partition order across multiple target shards,thereby rapidly partitioning the pending transactions.The target shards can reach consensus on received transactions without waiting for account data.The source shard subsequently sends the account data to the corresponding target shards in the order specified by the previously simulated partition transactions.Based on real transaction history from Ethereum,we conducted extensive sharding scalability experiments.By maintaining low cross-shard rates and a relatively balanced load distribution,HATLedger achieves throughput improvements of 2.2x,1.9x,and 1.8x over SharPer,Shard Scheduler,and TxAllo,respectively,significantly enhancing efficiency and scalability.
文摘BACKGROUND Drug utilization research has an important role in assisting the healthcare administration to know,compute,and refine the prescription whose principal objective is to enable the rational use of drugs.Research in developing nations relating to the cost of treatment is scarce when compared with developed countries.Thus,the drug utilization research studies from developing nations are most needed,and their number has been growing.AIM To evaluate patterns of utilization of antipsychotic drugs and direct medical cost analysis in patients newly diagnosed with schizophrenia.METHODS The present study was observational in type and based on a retrospective cohort to evaluate patterns of utilization of antipsychotic drugs using World Health Organization(WHO)core prescribing indicators and anatomical therapeutic chemical/defined daily dose indicators.We also calculated direct medical costs for a period of 6 months.RESULTS This study has found that atypical antipsychotics are the mainstay of treatment for schizophrenia in every age group and subcategories of schizophrenia.The evaluation based on WHO prescribing indicators showed a low average number of drugs per prescription and low prescribing frequency of antipsychotics from the National List of Essential Medicines 2015 and the WHO Essential Medicines List 2019.The total mean drug cost of our study was 1396 Indian rupees.The total mean cost due to the investigation in our study was 1017.34 Indian rupees.Therefore,the total mean direct medical cost incurred on patients in our study was 4337.28 Indian rupees.CONCLUSION The information from the present study can be used for reviewing and updating treatment policy at the institutional level.
文摘The new RE 6 EL from KARL MAYER brings a breath of fresh air to raschel fabric production.Nowadays textile companies increasingly need to produce small production runs and respond to market changes with instantaneous pattern changes in order to operate profitably–meaning they require machines that offer maximum flexibility,reliability and cost efficiency.KARL MAYER understands the challenges of the market and is launching its new RE 6 EL.The Raschel machine offers the core strengths of the classic RSE 6 EL and essentially the same performance parameters,but has been further cost-optimised largely due to local production advantages.This makes the newcomer an efficiency champion in production,especially when it comes to frequent pattern changes.
基金supported by State Grid Shanxi Electric Power Company Science and Technology Project“Research on key technologies of carbon tracking and carbon evaluation for new power system”(Grant:520530230005)。
文摘With the introduction of the“dual carbon”goal and the continuous promotion of low-carbon development,the integrated energy system(IES)has gradually become an effective way to save energy and reduce emissions.This study proposes a low-carbon economic optimization scheduling model for an IES that considers carbon trading costs.With the goal of minimizing the total operating cost of the IES and considering the transferable and curtailable characteristics of the electric and thermal flexible loads,an optimal scheduling model of the IES that considers the cost of carbon trading and flexible loads on the user side was established.The role of flexible loads in improving the economy of an energy system was investigated using examples,and the rationality and effectiveness of the study were verified through a comparative analysis of different scenarios.The results showed that the total cost of the system in different scenarios was reduced by 18.04%,9.1%,3.35%,and 7.03%,respectively,whereas the total carbon emissions of the system were reduced by 65.28%,20.63%,3.85%,and 18.03%,respectively,when the carbon trading cost and demand-side flexible electric and thermal load responses were considered simultaneously.Flexible electrical and thermal loads did not have the same impact on the system performance.In the analyzed case,the total cost and carbon emissions of the system when only the flexible electrical load response was considered were lower than those when only the flexible thermal load response was taken into account.Photovoltaics have an excess of carbon trading credits and can profit from selling them,whereas other devices have an excess of carbon trading and need to buy carbon credits.
基金Supported by the National Natural Science Foundation of China(11371284)
文摘We study the dividend optimization problem for an insurance company under the consideration of internal competition between different units inside company and transaction costs when dividends occur. The management of the company controls the reinsurance rate, the timing and the amount of dividends paid out to maximize the expected total dividends paid out to the shareholders until ruin time. By solving the corresponding quasi-variational inequality, we obtain the optimal return function and the optimal strategy.
基金Supported by the Natural Science Foundation of Zhejiang Province (Y604137) the Altitude College Natural Science Foundation of JiangSu Province (KY205017).
文摘The purpose of present work is to examine the financial problem of finding the universal reservation prices of a European call option written on exchange rate when there is proportional transaction costs of trading foreign currency in the market. An approach is suggested to compute the reservation bid-ask price of foreign currency call option based on maximizing the investor＇s expected utility. Option prices are determined from the investor＇s basic portfolio selection problem, without the need to solve a more complex optimization problem involving the insertion of the option payoffs into the terminal value function. Option prices are computed numerically in a Markov chain approximation for the case of exponential utility. Numerical results show that the option price bounds are almost independent of the alternative risk aversion parameter, but the bounds of NT region becomes narrower and the range of values of the initial holding for which the fair price lies within the bid-ask spread is shifted to a lower value when the risk aversion parameter increases.
文摘Global environmental meeting, legislating a reduction in the emission of greenhouse gases for planet earth, is what mankind now hopes for, having realized the enormous dangers in the process of climate change. Global warming is no longer denied by the so-called cornucopians （e.g. Lomberg）, but global policy-making originating in reunions of 190 governments or more stumble on collective action difficulties, spelled out in game theory. Paris will not succeed where Copenhagen failed, namely to arrive at a binding and enforceable global environment policy that will be implemented before it is too late. Instead, there will be massive transaction costs from negotiating and re-negotiating, endless voting, the making of promises exante and reneging ex post, as well as the futile attempts at any enforcement action, given state sovereignty. Mankind will have to learn how to cope with the outcomes of global warming, as resilience is the only hope.
基金Supported by the Key Grant Project of Chinese Ministry of Education (NO.309018)National Natural Science Foundation of China (NO.70973104,NO.11171304)Zhejiang Provincial Natural Science Foundation of China (NO.Y6110023)
文摘This paper concerns optimal investment problem with proportional transaction costs and finite time horizon based on exponential utility function. Using a partial differential equation approach, we reveal that the problem is equivalent to a parabolic double obstacle problem involving two free boundaries that correspond to the optimal buying and selling policies. Numerical examples are obtained by the binomial method.
基金supported by the National Natural Science Foundation of China (Grant Nos.70671064,70518001)
文摘In this paper, the discrete mean-variance model is considered for portfolio selection under concave transaction costs. By using the Cholesky decomposition technique, the convariance matrix to obtain a separable mixed integer nonlinear optimization problem is decomposed. A brand-and-bound algorithm based on Lagrangian relaxation is then proposed. Computational results are reported for test problems with the data randomly generated and those from the US stock market.
文摘This study examines the transaction costs of collaborative watershed management in the Cuyahoga River Area of Concern(AOC)—one of the 43 geographic areas designated by the U.S.and Canada Great Lakes Water Quality Agreement(GLWQA),where significant impairment of beneficial uses has occurred as a result of human activities.The Cuyahoga River is located in Northeast Ohio,the U.S.and flows through the City of Cleveland before draining into Lake Erie—one of the five Great Lakes of North America.The watershed is degraded due to municipal and agricultural discharges,streambank erosion,and contamination from urban and industrial sources.This research explores how a diverse group of stakeholders convened under the Cuyahoga River AOC Advisory Committee to share information,coordinate activities,agree on activities that restore beneficial uses,and support strategic management actions.In this study,23 semi-structured interviews with members of the advisory committee were conducted between January 28,2020 and April 20,2020,with follow-up emails and phone calls as needed to corroborate information.A review of research articles and government documents supported the interviews,including United States Environmental Protection Agency(U.S.EPA)and Ohio Environment Production Agency(OEPA)reports on the GLWQA and Cuyahoga River Remedial Action Plans.A third source of data is from direct participant observation at quarterly meetings of the advisory committee during 2017–2020,binational AOC conferences in 2017 and 2019,and other professional events geared towards restoring the Cuyahoga River AOC in 2016–2020.Results of this study include a set of recommendations to help guide group structure and decision-making processes,including(1)employing best available technology to organize AOC events and disseminate information;(2)supporting new members with an orientation and/or mentor to clearly define formal and informal committee rules;(3)assuring equal access to detailed information on management action plans with a real time dashboard;(4)updating voting procedures and the prioritization of management actions;and(5)better incorporating underrepresented local communities and highlevel decision makers from municipalities,government agencies,and nongovernmental organizations located within the Cuyahoga River AOC.Results help to explain the collaborative process within the advisory committee and measure the institutional performance of the advisory committee in terms of efficiency,equitability,accountability,and adaptability.
文摘To some two\|period economies with countable infinite state spaces, the existence of expectation equilibrium of real asset economies with transaction costs is given. This work extends the researches of Zame in 1993.
文摘This paper presents an empirical analysis of the effect that participation in an agricultural cooperative has on the transaction costs and net income of apple- growing farmers in Shandong province. Compared with independent farming, agricultural cooperatives reduce transaction costs by 48 yuan/mu and increase farmers＇ net income by 321 yuan/mu. Other factors found to influence transaction costs and farmers＇net income were farmer＇s gender, educational attainment, farm size, the availability of market information, distance to market, and level of government support. Independent farmers＂ most common explanations for not participating in agricultural cooperatives were that doing so would not reduce transaction costs significantly and that the cooperatives would impede the autonomy of their decision-making.
文摘Thucydides asserts that the occupation of Decelea by the Spartans in 413 BC made the grain supply for Athens costly by forcing the transport from land onto the sea.This calls into question the well-established consensus that sea transport was far cheaper than land transport.This paper contends that the cost of protecting supply lines-specifically the expenses associated with the warships which escorted the supply ships-rendered the grain transported on the new route exceptionally costly.In this paper,the benefits and drawbacks of a maritime economy,including transaction costs,trade dependencies,and the capabilities of warships and supply ships are discussed.
文摘We present a parallel algorithm that computes the ask and bid prices of an American option when proportional transaction costs apply to trading in the underlying asset. The algorithm computes the prices on recombining binomial trees, and is designed for modern multi-core processors. Although parallel option pricing has been well studied, none of the existing approaches takes transaction costs into consideration. The algorithm that we propose partitions a binomial tree into blocks. In any round of computation a block is further partitioned into regions which are assigned to distinct processors. To minimise load imbalance the assignment of nodes to processors is dynamically adjusted before each new round starts. Synchronisation is required both within a round and between two successive rounds. The parallel speedup of the algorithm is proportional to the number of processors used. The parallel algorithm was implemented in C/C++ via POSIX Threads, and was tested on a machine with 8 processors. In the pricing of an American put option, the parallel speedup against an efficient sequential implementation was 5.26 using 8 processors and 1500 time steps, achieving a parallel efficiency of 65.75%.
文摘The economic regionalization practice led by China local governments has gradually evolved into chaos. Local governments compete to declare for higher-leveled and large-scaled economic regions to obtain more economic resources and policy support in the way of policy game. The author argues that the regionalization chaos is attributed to the reason that the present theoretical support for economic regionalization overemphasizes the economic growth brought about by the economic regionalization but ignores the effect of transaction cost, which leads to constraint loss on the economic regionalization theory analysis framework. Then, the introduction of economic regionalization analysis framework based on the conflicts between scale expansion and transaction costs would establish equilibrium conditions to set up a moderate scale development for economic regions. The author hopes that the acceptance of this framework into the economic regionalization decision-making system would give guidance for making more appropriate regionalization decisions.
文摘The Bermudan option pricing problem with variable transaction costs is considered for a risky asset whose price process is derived under the information-based model. The price is formulated as the value function of an optimal stopping problem, which is the value function of a stochastic control problem given by a non-linear second order partial differential equation. The theory of viscosity solutions is applied to solve the stochastic control problem such that the value function is also the solution of the corresponding Bellman equation. Under some regularity assumptions, the existence and uniqueness of the solution of the pricing equation are derived by the application of the Perron method and Banach Fixed Point theorem.
基金Philosophy and Social Science Planning Projects in Yunnan Province,No.QN202428China Postdoctoral Science Foundation,No.2024M752918。
文摘Foreign-funded overseas industrial parks(OIPs)are crucial for attracting foreign investment and promoting globalization in developing countries.However,large-scale land acquisition for these parks generates conflicts between developers and local stakeholders,increasing development costs.A qualitative multicase study was conducted in this study to analyze the land transaction trajectories of China's OIPs.Four OIPs were selected to reveal the underlying mechanisms from the perspectives of institutional arrangements,governance mechanisms,and enterprise heterogeneity.The findings indicate that in host countries with insufficient institutional development,local governments are more inclined to directly engage in OIP land acquisition.High-level intergovernmental mechanisms facilitate land acquisition processes,although their efficacy depends largely on administrative power allocation across parks in host countries.The results also indicate that enterprise characteristics significantly influence land acquisition,where microscale private enterprises lacking political connections often employ low-cost,bottom-up strategies by leveraging international experience.In summary,policy-makers in developing countries should prioritize enhancing OIP governance to mitigate transaction costs,promote diversified land supply,and optimize land allocation.By depicting China's OIP land acquisition processes,this study deepens the academic understanding of OIP governance in developing countries and related international land transactions,offering practical OIP management insights for governments in both host and parent countries.
