Mean Price Research Articles

Investigating the Market Value of Brumbies (Equus caballus) in the Australian Riding Horse Market.

Feral horses, also known as brumbies, are widely distributed across Australia with some populations being managed largely by human intervention. Rehoming of suitable feral horses following passive trapping has wide community acceptance as a management tool. However, there is little information about the number and relative economic value of feral horses compared with cohorts in the riding horse market. We examined 15,404 advertisements of horses for sale in 53 editions of Horse Deals, published from February 2017 to July 2022. Despite the considerable media attention and public scrutiny surrounding feral horse management, rehomed feral horses represented only a tiny fraction of the horse market in the current study. Of the 15,404 advertisements examined, only 128 (0.0083%) were for feral horses. We recorded phrases used to describe behavioural characteristics and other variables. The following variables were found to be not independent: Ridden Status, Height, Age, Sex, Colour, and Warning terms/more work. Using descriptive statistics to describe basic features of the data, the average price for feral horses ($1408) was lower than that for domestic horses ($1790) with the maximum price for a domestic horse being nearly twice the maximum for a feral horse. Univariate analysis showed feral horses were over-represented among "Unbroken" horses and underrepresented among "Ridden", "Broodmare" and "Harness" horses compared with domestic bred horses (p < 0.001). Feral horses appeared over-represented at shorter heights, among younger age groups (3 years or younger and 3.1 to 6 years) (p < 0.001) and in the dilute colour category (p = 0.008). The multivariable mixed model on price revealed that for domestic horses, the highest estimated marginal mean price averaged across the colour categories was for ridden horses aged 6.1-10-year-old at $1657.04 (95% CI $1320.56-$2074.66). In contrast, for feral horses, the multivariable mixed model demonstrated the similar highest estimated marginal mean averaged was for green broken 3-6-year-old horses that have undergone foundation training under saddle at $2526.97 (95% CI $1505.63-$4208.27). Australian feral horses were valued differently tfromsimilar domestic horses in the recreational riding horse market and further research is warranted to determine appropriate target markets and boost the sustainability of rehoming as a feral horse management tool.

Price analysis of medicines used in general anesthesia before and after the SARS-CoV-2 pandemic: a retrospective observational study

Objectives: with the emergence of the pandemic in early 2020, there was an increase in the prices of medicines used in hospital anesthetic procedures. The main objective of this study was to assess the variations in prices of anesthetics used in general anesthesia procedures between the periods prior to and after the beginning of the SARS-CoV-2 pandemic. Methods: we investigated 105 anesthesic records of exploratory laparotomies or laparoscopic procedures performed in a private hospital in southern Brazil and analyzed the prices of medicines used in two general anesthesia techniques: total intravenous anesthesia (TIVA) and balanced anesthesia with anesthetic gases. We obtained the price of anesthetic procedures from records issued in the final trimesters of 2019, 2020, and 2021 (33, 43, and 29, respectively). Results: a statistically significant difference in prices was seen between periods for both techniques. The price of TIVA in 2019 was R$ 229.30/hour, in 2020 it was R$ 472.13/hour, and in 2021 it was R$ 247.38/hour. For balanced anesthesia, this price was R$ 66.32/hour in 2019, R$ 109.97/hour in 2020, and R$ 90.30/hour in 2021. In a post hoc analysis, significant differences were observed in the hourly prices of TIVA between 2019–2020 (p=0.01) and 2020–2021 (p=0.04); for balanced anesthesia, this was seen only in the 2019–2020 period (p=0.02). Conclusion: this study demonstrated significant increases in the mean prices of general anesthesia administered via intravenous (up to 36.36%) or inhalation (up to 89.47%) routes for exploratory laparotomies performed before and after the beginning of the SARS-CoV-2 pandemic in a private hospital in southern Brazil. However, no statistical difference in the hourly prices was observed between 2019 and 2021 for both anesthetic techniques.

Socio-Ecological Overview of the Greater Amberjack Fishery in the Balearic Islands

This study provides the first socio-ecological overview of the Seriola dumerili fishery occurring in the Balearic Islands. This pelagic top-predator is among the five most valued fish resources of the Balearic community. Despite its ecological importance and potential vulnerability to aggregation fishing, few studies address the ecology of this large Carangidae species. Shining a light on its ecology is vital to ensure adequate species conservation and the sustainable and effective management of the fishery. Historical catches from 1950–1999, alongside detailed landing data for the last 21 years, were analysed to identify potential patterns in ecological and socio-economic factors. Significant inter-annual variability among the years was found in historical catches of greater amberjack, while catches and mean prices of the different size categories revealed significant results between seasons and months, respectively. Additionally, the purse seine fleet accounted for the highest percentage of S. dumerili catches. CPUE did not appear to change greatly between months and years after the annual 8-month fishing ban imposed in 2011 and therefore a re-evaluation of the closure was intended. Overall, this study suggests seasonality influences the S. dumerili fishery in the Balearic Islands, within which ecological influences show a higher regulating power than socio-economic factors.

Physician Management Companies and Neonatology Prices, Utilization, and Clinical Outcomes.

Physician management companies (PMCs) acquire physician practices and contract with hospitals to provide physician management services. We evaluated the association between PMC-NICU affiliations and prices, spending, utilization, and clinical outcomes. We linked commercial claims to PMC-NICU affiliations and conducted difference- in-differences analyses comparing changes in prices paid for physician services per critical or intensive care NICU day, length of the NICU stay, physician spending (total paid amount for physician services during stay), spending on hospital services (total paid amount for hospital services during stay), and clinical outcomes in PMC-affiliated versus non-PMC-affiliated NICUs. The study included 2858 infants admitted to 34 PMC-affiliated NICUs and 92 461 infants admitted to 2348 NICUs without an affiliation. PMC affiliation was associated with a differential increase in the mean price of the 5 most common types of critical and intensive care days in NICU admissions by $313 per day (95% confidence interval, $207-$419) for PMC-affiliated versus non- PMC-affiliated NICUs. This represents a 70.4% increase in prices, relative to the preaffiliation period PMC and non- PMC-affiliated NICU means. PMC-NICU affiliation was also associated with a differential increase in physician spending by $5161 per NICU stay (95% confidence interval, $3062-$7260), a 56.4% increase. There was no significant association between PMC-NICU affiliation and changes in length of stay, clinical outcomes, or hospital spending. PMC affiliation was associated with large increases in prices and total spending for NICU services, but not with changes in length of stay or adverse clinical outcomes.

Price fairness: square equity and mean pricing

Prices have a leverage effect on firm profits. Prices, however, have also an impact on customer’s perceived price fairness and thus indirectly on firm’s bottom line. A growing body of literature shows this. Papers on the level of the fair price, however, are rather scarce. Based on different concepts of justice, two levels of fair prices are proposed: square equity and mean prices. I run an experiment which shows that both are considered fairer than cost-based or value-based prices. The results can be used to assess fairness implications of prices ex ante and hence complement traditional pricing approaches.

Comparison of Two Quantitative Strategies: Momentum and Mean-reversion

With the development of finance and computers, the field of quantitative finance is gradually gaining attention and research. In this paper, two classic trading strategies are chosen for comparisons (namely momentum strategy and mean reversion strategy) to select the performance of Tesla and Gold in the last decade as the research object. The Tesla and Gold both performances better in momentum strategy than in the mean-reversion strategy. According to the analysis, it demonstrates that volatile stocks are more likely to generate greater profits with a momentum strategy. However, volatile equities may not regress well to the mean price, or the rate of regression may be irregular, rendering a strategy based on mean reversion ineffective. This study presents a sample for comparing momentum and mean reversion techniques and develops the features of stocks that are suited for both momentum and mean reversion strategies. These results shed light on guiding further exploration of quantitative strategy.

CONCENTRATION OF DAIRY COW BREEDING AND COMPETITIVENESS OF POLISH FARMS SPECIALIZED IN MILK PRODUCTION

The article presents reasons for farmers to increase concentration in dairy cow breeding. The most important concerns the decrease in the unit profitability of milk production caused by a faster growth rate of labor costs and prices of means of production purchased by farmers than the selling prices of agricultural products. The result of the trends was a decrease in the number of dairy farms and the number of cows. In 1996-2020, the number of dairy farms decreased by 85% (to 198 thousand), and the number of cows decreased by 28.7% (to 2,468 thousand units). As a result, the average size of a herd of cows increased from 2.64 in 1996 to 12.64 units in 2020. At the same time, the milk yield of cows increased by 85%. The territorial diversification of the cow population also deepened. In 2020, 69.2% of the cow population was located in the following voivodships: Mazowieckie (21.1%), Podlaskie (18.9), Wielkopolskie (13.0%), Warmisko-Mazurskie (8.5%) and dzkie (7.7%). The analysis of the economic results of farms carried out in two periods 2008-2010 and 2018-2020 showed that farms with at least 24 cows with a total milk production of 129 tons in the first period and 144 tons of milk in the second period turned out to be able to compete. Farms with 62 cows with a total production of 494 tons of milk were fully competitive in the second period.

Diversity and characteristics of commercial Red Sea fish species based on fish market survey: informing management to reduce the risk of overfishing.

In small-scale fisheries (SSFs), where the sampling of many small boats and landing sites sometimes is not practical, fish market surveys represent an alternative way to obtain key fisheries data. This study analyses the diversity and characteristics of commercial Red Sea fish species landed in the Egyptian coast, including family, species-specific abundance, biomass, size and price by surveying the largest local fish market on the Egyptian Red Sea coast, over the course of a year (July 2021-June 2022) to also reflect any seasonality of these variables. Based on 53 survey visits, a total of 131,795 fish individuals, belonging to 111 species, and 22 families, were identified, recorded and measured. The analysis focused on the 60 most abundant species (104,420 individuals, 15 families). The surveys revealed that the most abundant families were Serranidae, Lethrinidae and Scaridae. Carangidae also was one of the most important families in terms of biomass. The most abundant species were Lethrinus mahsena, Sargocentron spiniferum and Lethrinus nebulosus. About 60% of revenue comes from the four families Serranidae, Lethrinidae, Scaridae and Lutjanidae. In terms of prices, the most expensive categories were species belonging to Serranidae, Lethrinidae and Lutjanidae families, such as Plectropomus pessuliferus marisrubri, Argyrops spinifer, L. nebulosus and Variola louti. The overall mean prices were higher in spring and summer months likely due to tourism flows. The mean size of many species, including the most valuable and abundant ones, is below the length of maturity. These results provide important benchmarks for monitoring future changes and shed important insights for fisheries management. Co-organised Dutch auctions would provide reliable data when combined with a strict monitoring effort to avoid any sale of the catch outside these official auctions. Other monitoring tools and methods are also recommended in the discussion.

Thermo-economic evaluation of a tri-generation system driven by geothermal brine to cover flexible heating and cooling demand

The main challenge for designing a tri-generation system is to fully cover the heating and cooling demand in district heating networks. In this work, a new flexible tri-generation system driven by geothermal brine is proposed and analysed from a thermo-economic point of view. The proposed system covers the demand of a specific district network according to the climate conditions in Germany. The tri-generation system includes the domestic heat exchanger, the Kalina cycle, and the absorption refrigeration cycle to produce heating, electricity, and cooling. The working fluid of the system is an NH3H2O mixture. The off-design calculation is applied to the design of the heat exchangers as well as to perform annual calculation. The sensitive analysis is studied to evaluate the influence of operational parameters on the system performances. The results show that the ambient temperature and geothermal mass flow division ratio play an indispensable role in the system performance. The mean annual exergy efficiency and levelized cost of electricity are calculated as 46.23% and 0.2245 $/kWh, respectively. An interest rate of less than 5% and the heating mean price greater than 0.15 $/kWh result in an LCOE of less than 0.15 $/kWh.

Publicly Disclosed Pricing for Common Upper-Extremity Procedures: An Analysis of Hospital Chargemasters.

American hospitals are required to provide price transparency data (known as a chargemaster) for medical services, which is intended to allow consumers to accurately estimate the cost of medical services. Our purpose was to identify hospital compliance in publishing chargemaster documents and to assess the price information published for common upper-extremity services and procedures. We performed a cross-sectional analysis of publicly available chargemaster data from 122 hospitals, which included the top-20-ranked Honor Roll hospitals from US News and World Report and 2 top-ranked hospitals from each state. Chargemaster files were accessed for each hospital, and price information was recorded for 10 common upper-extremity procedures including radiographs, injections, and surgeries. Mean procedural prices were compared between academic and nonacademic hospitals. Chargemaster files were able to be accessed for 107 (88%) of 122 institutions. Price estimates for imaging studies were more frequently reported (73%) than those of procedures (23%-41%). With 50 hospitals reporting a price estimate, carpal tunnel injection was the most frequently reported procedure, whereas trigger finger release was the least frequently reported (41% and 23%, respectively). Wide price ranges were noted, with mean charges for a total shoulder arthroplasty listed as US $51 723 (range, US $247-US $364 024). Mean prices between academic and nonacademic hospital systems were similar. While most (88%) of the included hospitals have been compliant with publishing their price transparency files, price estimates for common upper-extremity procedures and imaging studies are inconsistently reported and, when present, demonstrate high levels of price variability between and within hospital systems.

Dietary Costs among Midwestern Adult Food-Pantry Users by Food-Security Status.

Evidence of the relationship between dietary cost, diet quality, and socio-economic status is mixed. No studies have directly evaluated food-security status and dietary cost. This study investigated whether food-pantry clients with low and very low food-security status had less expensive daily diets than food-secure clients by comparing total cost, cost per gram, and cost per calorie of total daily dietary intake both per person and by individual food item, followed by evaluations of each food group. Mixed-model regression and Tukey-Kramer comparisons were used to compare food-security groups. There was no clear association between food-security status and cost of daily diet. Analyzed per person, total price and price per gram showed significant differences between low food-secure and food-secure groups. When analyzing individual food items, prices per calorie were significantly different between food-secure and very low food-secure groups. The directionality of the relationships by food-security status was inconsistent. Per person, those with lower food security had lower mean prices, and for individual foods this association was reversed. Therefore, the metric of food cost and the unit of analysis are critical to determining the relationship between food-security status and dietary cost.

Continuous-time modeling of financial returns based on Limit Order Book data

The Limit Order Book (LOB) of a financial security contains the list of buy and sell orders placed by traders on a single or across many exchanges for a given stock. As such, the amount of information contained in the LOB is much richer than that contained in the time history of the mean price, so it can potentially be exploited to model and predict more accurately the future returns. As far as we are aware, this work offers - for the first time - a dynamical systems perspective on the latter modeling problem, leading to a two-fold contribution: (i) we will define a new regressor, called Base Imbalance, and we will show that its predictive potential is more significant than the ones usually employed in the literature; (ii) we will discuss that the most suitable way to derive a model of the LOB dynamics is via continuous-time system identification, due to the event-based nature of the phenomenon at hand. The effectiveness of the proposed modeling strategy to be used in trading policies will be illustrated by means of a benchmark experimental data.

Analysis of the efficacy, safety, and cost of alternative forms of creatine available for purchase on Amazon.com: are label claims supported by science?

Creatine monohydrate (CM) is an established and effective dietary supplement, but it is not the only form of creatine. We analyzed forms of creatine for sale on Amazon.com" title = "http://Amazon.com">Amazon.com and evaluated if the advertised claims are supported by the available scientific evidence. We also analyzed the cost per gram of the forms of creatine. A total of 175 creatine supplements were included and we reported the total creatine content per serving, form(s) of creatine in products, product claims, and prevalence of products third party certified. The identified products contained 16 forms of creatine other than CM. The prevalence of products containing functional ingredients with CM or forms of creatine was 29.7%, and the prevalence of products containing blends of different forms of creatine was 21.7%. Only 8% of products were third party certified. The products using only CM (n = 91) had a mean price per gram of $0.12 ± 0.08, whereas products using only other forms of creatine (n = 32) had a mean price per gram of $0.26 ± 0.17. Approximately 88% of alternative creatine products in this study are classified as having limited to no evidence to support bioavailability, efficacy, and safety.

Dynamic Pricing and Mean Field Analysis for Controlling Age of Information

Today many mobile users in various zones are invited to sense and send back real-time useful information to keep the freshness of the content updates in such zones. However, due to the sampling cost in sensing and transmission, a user may not have the incentive to contribute real-time information to help reduce the age of information (AoI). We propose dynamic pricing for each zone to offer age-dependent monetary returns and encourage users to sample information at different rates over time. This dynamic pricing design problem needs to well balance the monetary payments as rewards to users and the AoI evolution, and is challenging to solve especially under the incomplete information about users’ arrivals and their private sampling costs. After formulating the problem as a nonlinear constrained dynamic program, to avoid the curse of dimensionality, we first propose to approximate the dynamic AoI reduction as a time-average term and successfully solve the approximate dynamic pricing in closed-form. Further, we extend the AoI control from a single zone to many zones with heterogeneous user arrival rates and initial ages, where each zone cares not only its own AoI dynamics but also the average AoI of all the zones in a mean field game system to provide a holistic service. Accordingly, we propose decentralized mean field pricing for each zone to self-operate by using a mean field term to estimate the average age dynamics of all the zones, which does not even require many zones to exchange their local data with each other.

Biosimilars of anti‐vascular endothelial growth factors for ophthalmic disease – Clinical trial status 2022

AbstractPurpose: Diabetic Macular Œdema (DME) and Age‐related Macular Degeneration (nAMD) are the leading causes of vision loss in developed nations. Anti‐Vascular Endothelial Growth Factor (aVEGF) has revolutionized the treatment of both conditions, but access is limited by costs. Biosimilars of aVEGF can cut costs, but prescriber concerns over the lack of clinical data can slow uptake. This paper reports all biosimilar aVEGF in development for Europe and the USA, and pools the results of clinical confirmatory trials to provide statistically greater reassurance in the similarity of outcomes.Methods: Biosimilars in the clinical development phase were identified from US and EU trial registries.Results: There are 13 biosimilars of ranibizumab and aflibercept in final clinical comparative trial stage of development in Europe and the USA, recruiting 6126 patients. Five studies of intravitreal bevacizumab biosimilars are recruiting 772 patients. Equivalence outcomes are typically based on Best‐Corrected Visual Acuity (BCVA) with 90% confidence limits of −3 to +3 letters between reference and biosimilar medicines. Completed trials to date with 1166 participants analysed together show BCVA outcomes of ≤1 letter between Originator Reference Products and Biosimilars; for serious adverse events the risk ratio is 1.17, with 95% confidence intervals of 0.85–1.63, p = 0.32.Conclusions: Biosimilars of aVEGF are expected soon. There are likely sufficient brands expected to create meaningful price competition. To date, the EU/US regulatory pathway is delivering biosimilars with close equivalence of safety and efficacy outcomes.

Using Supervised Machine Learning to Predict House Prices

Given the recent influx of prices in the housing market, determining a fair housing price has been of high interest for many homebuyers and sellers alike. In this project, various machine learning models are used to predict the price of a house based on physical features and characteristics such as lot size and neighborhood. Extensive data preprocessing and feature engineering were employed to aid the models’ performance compared to other models in the market. The best models have been able to predict U.S houses’ prices within a RMSE value of $23,000 when the mean price of a house in the dataset is $180,000. In future research, this model can be implemented in various other places within the U.S and additional features can improve performance further.

House Price Prediction Using Exploratory Data Analysis and Machine Learning with Feature Selection

In many real-world applications, it is more realistic to predict a price range than to forecast a single value. When the goal is to identify a range of prices, price prediction becomes a classification problem. The House Price Index is a typical instrument for estimating house price discrepancies. This repeat sale index analyzes the mean price variation in repeat sales or refinancing of the same assets. Since it depends on all transactions, the House Price Index is poor at projecting the price of a single house. To forecast house prices effectively, this study investigates the exploratory data analysis based on linear regression, ridge regression, Lasso regression, and Elastic Net regression, with the aid of machine learning with feature selection. The proposed prediction model for house prices was evaluated on a machine learning housing dataset, which covers 1,460 records and 81 features. By comparing the predicted and actual prices, it was learned that our model outputted an acceptable, expected values compared to the actual values. The error margin to actual values was very small. The comparison shows that our model is satisfactory in predicting house prices.

Linked Open Government Data to Predict and Explain House Prices: The Case of Scottish Statistics Portal

Accurately estimating the prices of houses is important for various stakeholders including house owners, real estate agencies, government agencies, and policy-makers. Towards this end, traditional statistics and, only recently, advanced machine learning and artificial intelligence models are used. Open Government Data (OGD) have a huge potential especially when combined with AI technologies. OGD are often published as linked data to facilitate data integration and re-usability. EXplainable Artificial Intelligence (XAI) can be used by stakeholders to understand the decisions of a predictive model. This work creates a model that predicts house prices by applying machine learning on linked OGD. We present a case study that uses XGBoost, a powerful machine learning algorithm, and linked OGD from the official Scottish data portal to predict the probability the mean prices of houses in the various data zones of Scotland to be higher than the average price in Scotland. XAI is also used to globally and locally explain the decisions of the model. The created model has Receiver Operating Characteristic (ROC) AUC score 0.923 and Precision Recall Curve (PRC) AUC score 0.891. According to XAI, the variable that mostly affects the decisions of the model is Comparative Illness Factor, an indicator of health conditions. However, local explainability shows that the decisions made in some data zones may be mostly affected by other variables such as the percent of detached dwellings and employment deprived population.

THE ECONOMIC AND PRODUCTION-RELATED SITUATION OF POLISH AGRICULTURE OVER THE PERIOD FROM 2015-2021

The aim of the study was to assess the economic and production-related situation of Polish agriculture during the COVID-19 pandemic. The analysis covered the years 2015-2021, i.e. in addition to the years of the pandemic’s occurrence in Poland (2020-2021), the research period included 5 earlier years, in order to identify possible changes during the pandemic. In order to attain the objective, the data from the Economic Accounts for Agriculture – EAA, published by Eurostat, was used. A library query and secondary data from the Eurostat database were employed. Over the years 2015-2021, the value and quantity of agricultural production in Poland increased. In the first year of the pandemic, the value of production increased nominally by 13.7%, and by 8% in real terms. This growth mainly stemmed from the increase in the volume of plant production. The second year of the pandemic brought a slight decrease in the production volume – by 0.8%. It resulted primarily from yield deterioration. The time of the pandemic was characterized by considerable changes in agricultural income. Unfavourable price changes in 2021, related to a large increase in costs, caused the income from agriculture rise in the first year of the pandemic, but over the second year of COVID-19, the income situation deteriorated significantly. Worse farming conditions related mainly to an increase in the cost of loans and the prices of production means may have a significant impact on the food security of the Polish society.

Which one to choose? A cost-effectiveness analysis between different technologies of air purifiers

Abstract Introduction CoViD19 pandemic highlighted the importance of air purifiers and, in commercialization, their performance and price influence the choice. Since primary focus concerns only performance in terms of CADR (Clean Air Delivery Rate), this study aims to compare: I) levels of declared air purifications according to different types of air purification technologies; II) price of them to evaluate if, with similar group-mean CADR (within +/- 1 SD), there are significant differences in selling prices. Methods A review of several devices was carried out, collecting data in January-April 2022. Four different types of air purifiers were considered, divided into as many groups: those equipped with HEPA filters + UV lamps, only with HEPA filters, only with UV lamps and those using other technologies. We applied Kruskal-Wallis test to evaluate statistical differences among prices normalized by CADR, at significant level of 0.05. Results Analysis was carried out on 186 devices: I) 37 had HEPA filters + UV lamps, II) 117 only HEPA filters, III) 11 only UV lamps and IV) 21 other technologies. Eight system had HEPA H11 (95% reduction of particle matter 0.5 μm), 8 had HEPA H12 (99.5%), 70 had HEPA H13 (99.95%), 11 had HEPA H14 (99.995%). The mean normalized costs of each group devices, in Euros/CADR were I) 1.22 (SD 2), II) 1.49 (SD 1.4), III) 7.63 (SD 7.38), IV) 1.22 (SD 0.99), respectively. Statistical comparison of four-group selling prices show significant differences (p &amp;lt; 0.05) due to the devices equipped with only UV lamps. Conclusions Comparison between technologies analyzed by mean price normalized to CADR showed significant differences between those that used only UV lamps compared to all the others. This is reasonably due to the fact that the use of only UV lamps requires radiant powers considerably greater than all the others, therefore also higher costs (about 5-6 times). In all cases, the level of disinfection reached, as declared, was always &amp;gt; 95%. Key messages • With the same mean price normalized to CADR, the selling price is significanly different only for devices equipped with UV lamps compared to all the others. • Choice of devices with a certain level of declared air purifications can be directed towards those with HEPA+UV/HEPA/other without the mean price normalized to CADR undergoing significant differences.