Period Of Prices Research Articles

Optimum pricing decision for the retailer with warranty and price-dependent variable demand

Buying inventory on a credit basis is an effective pricing plan, and trade credit is a popular component of market transactions that increase demand. In a dynamic situation, most businesses offer different rewards and services to their consumers under certain terms and conditions during commodity sales. The accompanying companies provide a warranty period facility to increase consumer demand for products. The holding cost often increases over time. This study determines a production model wherein the production rate is proportionate to the price-warranty period based on the demand rate with time-dependent holding cost and trade credit policy. This work leads to three vital conventions: (I) the rate of product demand is considered to be price-warranty period dependent; (II) the non-linear function is considered for the rate of replacement failure, wherein the capital of the manufacturer depends on the warranty period; and (III) the rate of inflation is constant; moreover, the present time value of money also measured. This study aims to find the selling price, cycle time, and warranty period by using an algorithm to optimize the total profit function of the manufacturer. The results are validated by solving three numerical examples with their graphical representation based on different situations and the major parameters, and sensitivity analysis is analyzed with important decision-making implications.

Bioeconomic modeling of on-growing Caribbean spiny lobster in Florida

The Caribbean spiny lobster fishery in Florida has recently shifted from supplying frozen tails in the domestic market to a higher value live export market, primarily in China. The fishery's seasonal landing pattern limits supply during periods of high demand and high price, resulting in lost revenue. In addition, about 25 % of lobster landings are unsuitable for the live export market. Of these lobsters, approximately 50 % are molting, and short-term live storage could make them viable for live export after molting is complete. We developed a bioeconomic model to examine the economic feasibility of on-growing wild-caught lobsters for sale later in the season when demand and price are higher. We also used the model to examine the feasibility and profitability of short-term aquaculture-based storage of molting lobsters for later sale in the live export market. The results suggest evidence of investment feasibility. Annual net returns and net present value to perpetuity were positive in all scenarios, but net returns were 359–1055 % higher in short-term storage of molting lobsters. Net present values to perpetuity ranged from $898,744 to $5,106,181. Cost of production ($/kg) ranged from $21.29 to $29.07, with the lowest cost for short-term storage of molting lobsters; however, this was also the most capital-intensive scenario, with costs more than five times that of the other scenarios. Risk analysis showed variations in stocking density, sale price, and survival of spiny lobsters were the major contributors to economic risk in longer-term on-growing scenarios, whereas sale price and input price were the major contributors in short-term storage of lobsters.

Research on systematic analysis and optimization method for ice storage cooling system based on model predictive control: A case study

Ice storage systems are commonly applied for space cooling in large-scale commercial buildings to realize cost-saving effects. However, the practical operation performance is far poorer than expected. This paper conducted field tests to study the operation performance of ice storage system in a commercial building located in hot summer and warm winter area in China. Where the mismatch between ice storage capacity of chiller plant and cooling demand of buildings was found the typical issue leading to insufficient ice storage in cooling season and over ice-storage in transition season. Thus the annual average COP of Ice-storage chillers and the annual EER of whole chiller plant only reached 3.19 and 2.53 respectively, and the cooling price reached 0.194 Yuan RMB/kWh. To address this, a control strategy based on a cooling load prediction model was implemented. The model inputs the easily obtainable parameters such as ambient meteorological conditions, working/rest days, and previous cooling load data to predict the cooling demand next day, and then to guide the daily ice storage capacity during valley electricity price period, as well as the cooperation of ice melting system and direct cooling system for space cooling. Therefore, significant energy and cost-saving effects were achieved, where the cost-saving rate reached 41.9%, and the cooling price decreased to 0.111 Yuan/kWh.

Multi-Time Scale Energy Storage Optimization of DC Microgrid Source-Load Storage Based on Virtual Bus Voltage Control

The energy storage adjustment strategy of source and load storage in a DC microgrid is very important to the economic benefits of a power grid. Therefore, a multi-timescale energy storage optimization method for direct current (DC) microgrid source-load storage based on a virtual bus voltage control is studied. It uses a virtual damping compensation strategy to control the stability of virtual bus voltage and establishes a virtual energy storage model by combining different types of distributed capability units. The design of an optimization process for upper-level daily energy storage has the objective function of maximizing the economic benefits of microgrids to cope with unplanned fluctuations in power. A real-time energy-adjustment scheme for the lower level is introduced, and a real-time energy-adjustment scheme based on virtual energy storage for the short-term partition of the source-load storage is designed to improve the reliability of microgrid operations. The experiment shows that, in response to the constant amplitude oscillation of the power grid after a sudden increase in power, this method introduces a virtual damping compensation strategy at 20 s, which can stabilize the virtual bus voltage. From 00:00 to 09:00, the battery power remains at around 4 MW, and from 12:00 to 21:00, the battery exits the discharge state. The economic benefits from applying this method are significantly higher than before. This method can effectively adjust the source-load energy storage in real time. During peak electricity price periods, the SOC value of supercapacitors is below 0.4, and during normal electricity price periods, the SOC value of supercapacitors can reach up to 1.0, which can make the state of the charge value of supercapacitors meet economic requirements.

Comprehensive evaluation of CCUS technology: A case study of China's first million-tonne CCUS-EOR project

CCUS, an emerging technology for reducing carbon emission, plays a crucial role in achieving the goal of carbon neutrality. CCUS technology exemplified by CO2 enhanced oil recovery (EOR) is gradually progressing from project demonstration to large-scale application. However, the commercial application still faces uncertainties in economic cost, energy efficiency and environmental benefits. This paper takes China's first million-tonne CCUS-EOR project (Qilu Petrochemical-Shengli Oilfield CCUS-EOR project) as an example, and establishes a comprehensive research framework for evaluating CCUS from the three dimensions of energy, environment, and economy, based on economic viability, energy input-output analysis, and carbon input-output analysis. The results demonstrate that during the project lifecycle, when the average oil price is $90/bbl, the project's NPV is $56.09 million, the project's IRR is 13.4 %, the payback period is 8.34 years, and the threshold oil price for the project to be economically profitable is $81.52/bbl. Furthermore, the Energy Return on Investment (EROI) of the project is 9.09, which considerably superior to that of the Shengli Oilfield's non-EOR, and the net energy output is approximately 18,472.57 kilobarrels. The Carbon Return on Investment (CROI) of the project is 4.12, with significant environmental benefits, and the cumulative net carbon emission reduction is approximately 8078.55 kilotonnes. Furthermore, the trends in EROI and CROI of the CCUS-EOR project demonstrate nearly opposite trajectories. The variation trends in EROI emerge N-shaped curve, while that of CROI emerge S-shaped curve. In summary, the Qilu Petrochemical-Shengli Oilfield CCUS-EOR project exhibits notable advantages in terms of energy efficiency and environmental benefits. However, the threshold oil price for triggering economic profitability is relatively high, which may pose certain economic risks to investors during periods of low oil price.

Adaptive Operation Strategy of a District Cooling System with Chilled Water Storage and Its Validations by OpenModelica Modeling and Simulations

Developing operation strategies for district cooling systems with chilled water storage is challenging due to uncertain fluctuations of cooling demand in actual operations. To address this issue, this paper developed an adaptive operation strategy and performed its validations by modeling and simulating a commercial cooling system in Shanghai using OpenModelica. Firstly, the originally designed operation strategy of the cooling system was evaluated by simulation but was found unable to meet the statistically averaged ideal cooling requirements due to the early exhaustion of stored chilled water at about 5:30 PM. Then, to build foundations for adaptive operation strategy development, a newly designed operation strategy was established by increasing the operation time of base load chillers in the valley and flat electricity price periods. The new strategy proved numerically sustainable in satisfying the ideal cooling demand. Moreover, to realize the strategy’s adaptability to actual cooling load fluctuations, an adaptive operation strategy was developed by tracking the target stored chilled water mass curve that was calculated by implementing the newly designed strategy. The simulation results verify that the adaptive operation strategy enables good adaptability to representative cooling load fluctuation cases by automatically and periodically adjusting the operation status of base load chillers. The adaptive operation strategy was then further widely numerically tested in hundreds of simulation cases with different cooling load variations. The time-lagging problem resulting in strategy failures was found in numerical tests and was addressed by slightly modifying the adaptive strategy. Results indicate that the adaptive operation strategy enables adaptability to deal with cooling demand fluctuations as well as allowing low cooling supply economic costs and power grid-friendly characteristics. This study provides theoretical support to strategy design and validations for district cooling system operations.

Time-varying effects of structural oil price shocks on financial market uncertainty

This study employed the structural oil price decomposition method proposed by Ready (2018) to decompose oil price shocks into oil risk shocks, demand shocks, and supply shocks. By using the Diebold and Yilmaz (DY) spillover index and rolling window methods, the static and dynamic spillovers of structural oil price shocks on financial market uncertainty were examined. The findings suggest that oil risk shocks exhibited the strongest spillover effects on financial market uncertainty (except for South Africa), followed by oil demand shocks, while oil supply shocks had virtually no impact. Second, the effects of structural oil price shocks on financial market uncertainty were time-varying. Third, significant differences in the spillover effects of structural oil price shocks on financial market uncertainty were found across countries, and the spillover effect of oil risk shocks on the financial market uncertainty in the United States was the largest in all periods. Fourth, the spillover effects of oil demand shocks on financial market uncertainty were larger in the high than in the low oil price period (except for Japan). Finally, during the COVID-19 (coronavirus disease) pandemic compared with the pre-epidemic period, the spillover effects of oil risk shocks on the financial market uncertainty in China significantly decreased, while simultaneously, the spillover effects of oil supply shocks on the financial market uncertainty in Australia substantially increased.

The new era of turbulence: Peacemaking trends in post-carbon times

Based on an empirical comparison of peace processes in carbon-dependent economies over time, this article investigates the impact of decarbonization and the related declining availability of political finance on peacemaking. While the period of high oil prices in the mid-2000s saw a small number of peace deals that attempted comprehensive settlements, the decline of oil prices in the years from 2014 resulted in a new era of turbulence. The turbulence is characterized by a high number of peacemaking attempts that strongly lean toward conflict management rather than resolution. The reasons for this new turbulence are twofold: the available means for substantial “buy-in,” into a political marketplace by ruling elites in carbon-dependent conflictive political marketplaces have vanished while, at the same time, the strategic interest of international powers in geopolitical stability and their willingness and capability to invest in such stability has declined.

Price Cannibalization Effect on Long-Term Electricity Prices and Profitability of Renewables in the Baltic States

This paper aims to evaluate price cannibalization effects in forecasts of long-term electricity prices and substantiate their relevance on the profitability of renewables in the Baltic States from 2024 to 2033. Statistical data analysis, literature review, scenario method, and PLEXOS modeling were applied. Five scenarios were analyzed for developing renewable energy sources (RES) and load in Lithuania. In contrast, scenarios for Estonia and Latvia were based on assumptions derived from the countries’ national RES strategies. The results showed that the increase in RES capacities will halve electricity market prices from around 130 EUR/MWh in 2024 to 58 EUR/MWh in Latvia, 60 EUR/MWh in Estonia, and 60–77 EUR/MWh in Lithuania in 2033. In time-waving, the absolute and relative price cannibalization effects of renewables were found. In 2033, the loss of revenue from solar photovoltaic (PV) generators was estimated to be 5.5–17.0 EUR/MWh in Lithuania, 7.1 EUR/MWh in Latvia, and 5.6 EUR in Estonia. The case of onshore wind demonstrated revenue losses of 10.5–22.0 EUR/MWh in Lithuania, 12.0 EUR/MWh in Latvia, and 10.0 EUR/MWh in Estonia. After 2029, revenues received by RES electricity generators could not guarantee project profitability; therefore, market flexibility options will be required. The key innovative strategy to mitigate the price cannibalization effect is the demand-side response when leveraging demand flexibility. Typically, this is achieved by sending price signals to the consumers who, if they have any, shift their demand to lower price periods. This is easily applied within HVAC systems, smart electric vehicle charging, and smart home appliance usage. Such behavior would allow the price cannibalization effect to be decreased.

PRICING SYSTEM IN LAND LEASING IN REVIEW OF IJĀRAH 'ALA AL-MANĀFI' CONTRACT

In the fiqh context of land leasing, there are variations in scholarly opinion regarding the legality and conditions of leasing. Some scholars argue that the leased land must provide direct benefits to the tenant, such as for agriculture, while others allow leasing for commercial activities. Rental pricing is a major concern as factors such as location, economic potential and land condition affect the rental value. This study aims to determine the system of determining land rental prices for business premises in the perspective of the ijarah 'ala al manafi' contract. Qualitative methods are used with observation and interview techniques to understand the practice of leasing in the perspective of Islamic economics. From this research, the results obtained in the practice of leasing land in Krueng Barona Jaya District, the principles of Islamic law, especially in the ijârah 'ala al-manâfi' contract, have generally been followed, including clarity of object, price, and time period. However, there is a discrepancy in terms of land benefits that cannot be obtained directly, which according to the view of the Shafi'iyah scholars, states that the benefits of the lease must be used immediately. Therefore, there needs to be more attention in ensuring the agreement is in accordance with the provisions of fiqh so that all parties get fair rights and obligations, and to achieve blessings in every transaction.

How rising housing prices affect labor costs in China: Heterogeneity and lagging

AbstractThe impact of house prices rising on urban labor costs has typical heterogeneity and lag effects, but there is little literature on it. Based on the panel data of 283 prefecture level cities from 2001 to 2017, we constructed panel model considering lag effect and threshold effect. The results show that lag one period of housing price has significant positive impact on urban labor costs, with the increase of housing prices, the effect of pushing up the current labor costs is gradually increasing. So, this impact has obvious lag effect and threshold effect. Through grouped regression to test heterogeneity effect, at the regional level, the heterogeneity of the impact is more significant. The more developed the economy is, the greater the pushing effect of house prices on labor costs.

A two-phase production inventory model for imperfect quality items with multivariate demand, upstream and downstream credit period offers under a carbon tax, and green subsidy

Generating customer-friendly products is a big task nowadays. Green products are famous all over the world now. In quite few manufacturing processes, carbon emissions become an unavoidable fact. To reduce emissions, the government enacted enormous rules and regulations. This developed model consists of a supply chain with two phase production containing defective products and rework through the same manufacturing system, where the product deterioration is considered after production and rework (i.e. where the deterioration starts when the product is out for sale), as three cases: (1) no deterioration, (2) instantaneous deterioration and (3) non-instantaneous deterioration. Demand function is selling price, green product price, advertisement and credit period dependent for first two cases and for case 3, the market scale of the demand is exponentially increasing considering uncertainty. Supplier offers a full credit period offer to the retailer and the retailer gives a partial credit period offer to his customer. Various methods are implemented to reduce carbon emissions during various production processes, and we have implemented preservation technology to reduce emissions even with a carbon tax policy involved. With government subsidies, the greenness of the product is considered to make it more environmental friendly. Numerical examples and sensitivity analysis are carried out to verify the results of the developed model.

Is there a “Flight to liquidity” phenomenon in the Saudi stock market?

The study examines how market illiquidity shocks affect stock prices and explores the "flight to liquidity" phenomenon in the largest stock market in the Middle East, specifically the Saudi stock market. It analyzes the relationship between these shocks and stock prices to understand the impact on both small and large firms. Utilizing a comprehensive database that contains daily data of all stocks listed on the Saudi stock market for over 20 years, the research evaluates the illiquidity of each stock and the entire market on a weekly basis. Market illiquidity shocks are determined using an autoregressive model, and the effect of these shocks on Saudi stock prices is assessed through illiquidity betas in linear regressions for both large and small firms. Initial findings show that illiquidity shocks were significant during periods of oil price declines and global financial crises. The results confirm that stock prices fall in response to market illiquidity shocks, with the impact varying by firm size; larger firms' stocks are less affected, indicating a flight to liquidity towards larger firms during market downturns. This pattern aligns with observations in the US and some emerging markets.

Investigation of the effects of synthetic wind speed parameters and wind speed distribution on system size and cost in hybrid renewable energy system design

The accuracy of wind speed data has an important impact on determining power output from a Hybrid Renewable Energy System including wind turbine. For a better estimation of energy price or payback period, it is crucial to determine both monthly average wind speed values and distribution parameters. Studies evaluating the sensitivity of wind speed distribution parameters concerning the optimal system size are lacking in the literature. This work fills the gap in the literature and for the first time, the effects of wind speed distribution parameters and wind speed distribution on the optimum system are statistically demonstrated. According to this case study, if these parameters are not set correctly, the Cost of Energy may be faulty between −14.024% and +37.804% for the Photovoltaic-Wind-Battery-Inverter system, may be faulty between −19.024% and +97.05% for the Wind-Battery-Inverter system and may be faulty between −56.437% and +65.250% for the Wind-Inverter system. When the default distribution parameters of the HOMER software are used, the errors are −0.609%, −18.30%, −34.215% respectively. This study reveals that in addition to monthly average wind speed values, distribution parameters should be chosen as accurately as possible. The innovative aspect of this work is the statistical presentation of how synthetic wind speed distribution can affect Hybrid Renewable Energy System sizing and at the same time Cost of Energy. Its importance is that it provides more precise results by guiding optimization studies using synthetic meteorological data, which is a popular field of study.

Peasant Resistance in Times of Economic Affluence: Lessons From Paraguay

Contrary to the established belief that low agricultural prices fuel peasant rebellion, our study investigates the surge in peasant unrest during a period of high agricultural prices. The transition to capital-intensive agriculture, characterized by reduced labor demand and heightened entry barriers, prompts landowners to expand into the agricultural frontier during periods of price increases. In these frontier regions, the soils, while comparatively less suitable, become economically viable for commercial agriculture when crop prices are high. This scenario sets the stage for heightened collective resistance, particularly where organizational capacities and subsistence communities provide peasants with symbolic and material resources to resist land encroachment. We provide evidence of this argument by using unique municipal-level data from Paraguay between 2000 and 2014, a period of rising yet fluctuating prices. Our study shows how the interplay between technological advancements in agriculture and global market forces reshape the geography of peasant rebellion.

Robust Unit Commitment With Decision-Dependent Uncertain Demand and Time-of-Use Pricing

Two-stage robust unit commitment (UC) is nowadays an effective decision-making model to support power system operations under uncertainty. This study extends the classical robust UC model to a novel formulation where the set of uncertain demand endogenously depends on the first-stage price decisions. We employ a generic time-of-use (ToU) pricing scheme, in a regulated system, to determine the optimal peak and off-peak price rates and periods of individual load buses. To exactly compute such ToU-based robust UC with decision-dependent demand, we customize and implement a <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">parametric</i> variant of the column-and-constraint generation method to handle this complex program with a changing uncertainty set. The proposed model and the computational performance of the solution method are illustrated on two typical systems, and experimental results are discussed with a set of novel insights.

Sustainable supply chain planning with the flexible provisions of inter-period emission credits borrowing and banking under a multi-period carbon trading scheme

Although the carbon emission trading regulation proves its advantage of reducing abatement costs, the timing of operating activities makes overage or shortage of allocated emission allowances quickly happen in single-year compliance, thus increasing abatement costs. The provision of inter-period emission credits banking and borrowing in a multi-period compliance phase can give emitters flexibility in emission compliance, which practices world-widely. In this study, we investigate the impact of carbon trading with inter-temporal emission credits borrowing and banking on a production–inventory–distribution system’s supply chain network decision-making and its compliance strategies by proposing a novel two-stage stochastic programming. A scenario-based robust optimization approach is presented with a post-optimization stage to obtain robustness-profit-environment balanced decision-making considering uncertain demand and stochastic carbon-trading price. The results suggests emitters should adopt specific greener techniques to reduce related emissions with priority under carbon-trading policies. The results also show the provision of carbon credits borrowing and banking has a positive influence on enhancing the efficiency in supply chain economic and ecological performance. Besides, given the flexible provisions, the manager can reallocate emission credits according to its business’s operation, and transfer more emission credits to periods of higher carbon-trading price. This findings also suggest banking in early periods instead of carelessly borrowing from future, for uncertainty in future business might make it harder or impossible to comply with emission regulation at last. To regulators, it should prevent borrowing explicitly or allow it only to a limited extent.

Global oil price and stock markets in oil exporting and European countries: Evidence during the Covid-19 and the Russia-Ukraine war

The relationship between oil price movements and stock markets during the COVID-19 pandemic and the geopolitical crisis like the ongoing Russian-Ukraine war is yet unexplored extensively. This study therefore examines the return-correlation effects of oil prices on stock markets and their spillover effects in oil-exporting and European countries using daily closing data. After estimating the GARCH process, we employ the static and dynamic Markov Switching model that allow the relationship between oil price and stock market to switch between two regimes coined the COVID-19 and the Russia-Ukraine war periods. The static model shows stock price returns to respond positively and significantly to oil price returns in Italy, Germany and the US during the Covid-19 period while the response is significantly positive only for US in the Russia-Ukraine war period. As regards the volatility spillover, significant spillover is found from stock to oil market for Nigeria, vice versa for Saudi Arabia and bi-directional volatility spillover found for the US, Italy and Germany during the COVID-19 period. The policy implication is that Nigeria and Saudi Arabia should prioritize financial policy and energy policy respectively while US, Italy and Germany should adopt policy coordination to stabilize oil-stock market volatility during low oil price period like the COVID-19 period.

Inventory model for green products with payment strategy, selling price and green level dependent demand using teaching learning based optimization algorithm

There has been a lot of research on pricing and lot-sizing practices for different payment methods; however, the majority has focused on the buyer’s perspective. While accepting buyers’ credit conditions positively impacts sales, requesting advance payments from purchasers tends to have a negative effect. Additionally, requiring a down payment has been found to generate interest revenue for the supplier without introducing default risk. However, extending the credit period, along with offering delayed payment options, has the potential to increase sales volume, albeit with an elevated risk of defaults. Taking these payment schemes into account, this study investigates and compares the per-unit profit for sellers across three distinct payment methods: advance payment, cash payment, and credit payment. The consumption rate of the product varies non-linearly not only with the time duration of different payment options but also with the price and the level of greenness of the product. The utmost objective of this work is to determine the optimal duration associated with payment schemes, selling price, green level, and replenishment period to maximize the seller’s profit. The Teaching Learning Based Optimization Algorithm (TLBOA) is applied to address and solve three numerical examples, each corresponding to a distinct scenario of the considered payment schemes. Sensitivity analyses confirm that the seller’s profit is markedly influenced by the environmental sustainability level of the product. Furthermore, the seller’s profitability is more significantly affected by the selling price index compared to the indices of the payment scheme duration and the green level in the demand structure.

Have the Chinese national oil companies paid too much in overseas asset acquisitions?

This paper provides both a quantitative and qualitative analysis of whether the Chinese national oil companies have “overpaid” than their international counterparts in overseas asset acquisitions during 2001–2017. Using a hedonic pricing framework, we find that while the Chinese companies did not pay more than international oil companies for the period of 2001–2008, there is statistically significant evidence that they overpaid during the 2009–2016 period. A counterfactual analysis was conducted to quantify the extent of the overpayment. Interviews and qualitative analysis suggest that the overpayment mainly results from a rush to gain projects in a period of high oil prices and easier bank loans after the global financial crisis rather than concerns about energy security or other political considerations.