Comments on a model of retail price inflation

1990 ◽  
Vol 117 (2) ◽  
pp. 407-413 ◽  
Author(s):  
A. Kitts
Keyword(s):  
Statistical Tests ◽  
Retail Price ◽  
Financial Model ◽  
Price Inflation

AbstractThe paper comments on the estimation and sensitivity of the retail price inflation component of the stochastic financial model proposed by Professor Wilkie. Statistical tests provide evidence of nonindependence and non-normality of residuals, suggesting non-linearity. However, it is noted that the model is most sensitive to the assumption of long-term mean inflation.

scholarly journals Statistically rigorous calculations do not support common input and long-term synchronization of motor-unit firings

2014 ◽  
Vol 112 (11) ◽  
pp. 2729-2744 ◽  
Author(s):  
Carlo J. De Luca ◽  
Joshua C. Kline
Keyword(s):  
Motor Unit ◽  
Statistical Tests ◽  
Vastus Lateralis ◽  
Common Input ◽  
Data Set ◽  
Order Of Magnitude ◽  
Score Method ◽  
Surface Electromyographic Signal ◽  
Measure Synchronization

Over the past four decades, various methods have been implemented to measure synchronization of motor-unit firings. In this work, we provide evidence that prior reports of the existence of universal common inputs to all motoneurons and the presence of long-term synchronization are misleading, because they did not use sufficiently rigorous statistical tests to detect synchronization. We developed a statistically based method (SigMax) for computing synchronization and tested it with data from 17,736 motor-unit pairs containing 1,035,225 firing instances from the first dorsal interosseous and vastus lateralis muscles—a data set one order of magnitude greater than that reported in previous studies. Only firing data, obtained from surface electromyographic signal decomposition with >95% accuracy, were used in the study. The data were not subjectively selected in any manner. Because of the size of our data set and the statistical rigor inherent to SigMax, we have confidence that the synchronization values that we calculated provide an improved estimate of physiologically driven synchronization. Compared with three other commonly used techniques, ours revealed three types of discrepancies that result from failing to use sufficient statistical tests necessary to detect synchronization. 1) On average, the z-score method falsely detected synchronization at 16 separate latencies in each motor-unit pair. 2) The cumulative sum method missed one out of every four synchronization identifications found by SigMax. 3) The common input assumption method identified synchronization from 100% of motor-unit pairs studied. SigMax revealed that only 50% of motor-unit pairs actually manifested synchronization.

scholarly journals Early and long-term complications following transanal pull through Soave technique in infants with Hirschsprung's diseaseric infants with Hirschsprung's disease

2019 ◽  
Author(s):  
Manoochehr Ghorbanpour ◽  
Mohammad Ali Seyfrabie ◽  
Babak Yousefi
Keyword(s):  
Intestinal Obstruction ◽  
Hirschsprung's Disease ◽  
Hirschsprung’S Disease ◽  
Statistical Tests ◽  
Case Series ◽  
P Value ◽  
Short Term ◽  
Case Series Study ◽  
The Mean

Objective. Patients undergoing Soave surgery for Hirschsprung's disease are at risk for some complications. The aim of this study was to investigate such short-term and long-term complications and evaluate the outcome of the operation in these patients. Methods. A case series study was carried out during the last 12 years, during 2007 to 2018 in Besat hospital of Hamadan. Data collection conducted using a checklist includes questions about demographic information, clinical features, and short-term and long-term complications, and consequences of post-operative surgery. The findings of the study were analyzed using SPSS software version 20 and appropriate statistical tests. P-value less than 0.05 was considered statistically significant. Results. A total of 55 children underwent Soave surgery during the last 12 years in Besat Hospital Hamadan, Iran. The mean age of the patients was 38±10 days during surgery, of which 56.4% were female. The mean hospital stay was 7.3 days. Also, the mean weight of children at birth was 2970±447 gr. Most of the patients were born as NVD (52.7%) and term (74.5%). The most common comorbidity was congenital heart disease. The most common short-term complication was intestinal obstruction in 14 patients (25.5%) and the most frequent long-term complication was intestinal obstruction and constipation (27.3% each cases). The mortality rate of patients in this study was 14.5% in total. Conclusions. One stage surgical procedure in Hirschsprung's disease is a safe and effective method, but care should be taken in choosing patients and patients should be monitored for possible complications, so that they can be considered and implemented for proper treatment.

Field trips for sustainable transport education

2018 ◽  
Vol 29 (4) ◽  
pp. 1424-1450 ◽  
Author(s):  
Lisa-Maria Putz ◽  
Horst Treiblmaier ◽  
Sarah Pfoser
Keyword(s):  
Behavioral Intentions ◽  
Statistical Tests ◽  
Effective Means ◽  
Panel Study ◽  
Field Trips ◽  
Learning Performance ◽  
School Type ◽  
Sustainable Transport ◽  
Content Type

Purpose Field trips can change students’ attitudes and improve their learning performance, but they have rarely been investigated in logistics education research. The purpose of this paper is to present the findings from field trips that were designed to increase students’ knowledge of sustainable transport as well as to change their attitudes and behavioral intentions. Design/methodology/approach A total of 104 logistics students participated in this longitudinal panel study. Non-parametric statistical tests were used to test for significant effects. Findings Field trips build students’ knowledge, improve their attitudes and increase their behavioral intentions to use sustainable transport modes in the short and in the long term. Gains in knowledge exceed the results expected from traditional learning theories. Gender and school type are important moderating variables. Gender did not play an important role for knowledge gains, but for attitude and behavioral intentions. Research limitations/implications More research is needed to generalize the findings to other populations and longitudinal panel studies are necessary to investigate a long-term effect of field trips. Practical implications Field trips are an effective means for successful knowledge transfer and are suitable to trigger attitudinal and behavioral changes. The involvement of practitioners and the hands-on experience ensure that students combine theoretical with practical knowledge. Originality/value This is the first longitudinal panel study that investigates the effects of logistics field trips, which were developed collaboratively by industry, educational and research institutions.

An investigation on fuel carrier’s price rise impacts on the consumer price inflation in Iran

2021 ◽  
Vol 04 ◽  
Author(s):  
Nima Norouzi
Keyword(s):  
Consumer Price Index ◽  
Commodity Prices ◽  
Gasoline Prices ◽  
Government Control ◽  
Short Term ◽  
Fuel Price ◽  
Price Inflation ◽  
Oil Derivatives ◽  
The Impact

Introduction: Oil is one of the primary commodities of all countries globally and is, in essence, the energy base of all that we know as transportation. Therefore, price fluctuations of derivatives, especially fuel and oil derivatives, are the policymakers’ main concerns because they can cause serious problems, such as inflation in commodity prices. Objective: The impact of fuel carriers’ prices on the consumer price index remains a subject of debate and research. This paper aims to develop a model to define the inflation regime in Iran and then investigate the impact of gasoline and diesel price on the total inflation rate. Method: In this study, using the central bank time series and available data on energy balance and World Bank data banks, a non-linear distributed online delay regression modeling is developed to analyze the relationship between fuel price and essential commodity inflation. Results: The results show that there is an impact of gasoline price on inflation. It does not have much effect in the long term, but diesel can somewhat influence raising prices, which can exacerbate poverty in the community that needs special attention. Conclusion: It was also found that diesel’s price is harmful to the economy because it can stimulate inflation in the long term. However, in the short term, diesel does not cause any significant inflation in the prices. While gasoline prices can have many short-term social effects, this paper suggests that the Iranian government control diesel fuel prices prevent long-term inflation in inflation and consumer price rate.

scholarly journals Urinary Estrogen Metabolites and Long-Term Mortality Following Breast Cancer

2020 ◽  
Vol 4 (3) ◽  
Author(s):  
Tengteng Wang ◽  
Hazel B Nichols ◽  
Sarah J Nyante ◽  
Patrick T Bradshaw ◽  
Patricia G Moorman ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Confidence Intervals ◽  
Proportional Hazards ◽  
Statistical Tests ◽  
Breast Cancer Mortality ◽  
Cox Proportional Hazards ◽  
Urine Collection ◽  
Estrogen Metabolites ◽  
All Cause Mortality

Abstract Background Estrogen metabolite concentrations of 2-hydroxyestrone (2-OHE1) and 16-hydroxyestrone (16-OHE1) may be associated with breast carcinogenesis. However, no study has investigated their possible impact on mortality after breast cancer. Methods This population-based study was initiated in 1996–1997 with spot urine samples obtained shortly after diagnosis (mean = 96 days) from 683 women newly diagnosed with first primary breast cancer and 434 age-matched women without breast cancer. We measured urinary concentrations of 2-OHE1 and 16-OHE1 using an enzyme-linked immunoassay. Vital status was determined via the National Death Index (n = 244 deaths after a median of 17.7 years of follow-up). We used multivariable-adjusted Cox proportional hazards to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the estrogen metabolites-mortality association. We evaluated effect modification using likelihood ratio tests. All statistical tests were two-sided. Results Urinary concentrations of the 2-OHE1 to 16-OHE1 ratio (>median of 1.8 vs ≤median) were inversely associated with all-cause mortality (HR = 0.74, 95% CI = 0.56 to 0.98) among women with breast cancer. Reduced hazard was also observed for breast cancer mortality (HR = 0.73, 95% CI = 0.45 to 1.17) and cardiovascular diseases mortality (HR = 0.76, 95% CI = 0.47 to 1.23), although the 95% confidence intervals included the null. Similar findings were also observed for women without breast cancer. The association with all-cause mortality was more pronounced among breast cancer participants who began chemotherapy before urine collection (n = 118, HR = 0.42, 95% CI = 0.22 to 0.81) than among those who had not (n = 559, HR = 0.98, 95% CI = 0.72 to 1.34; Pinteraction = .008). Conclusions The urinary 2-OHE1 to 16-OHE1 ratio may be inversely associated with long-term all-cause mortality, which may depend on cancer treatment status at the time of urine collection.

Measurement Requirements for Climate Monitoring of Upper-Air Temperature Derived from Reanalysis Data

2006 ◽  
Vol 19 (5) ◽  
pp. 854-871 ◽  
Author(s):  
Dian J. Seidel ◽  
Melissa Free
Keyword(s):  
Air Temperature ◽  
Statistical Tests ◽  
Reanalysis Data ◽  
Climatic Data ◽  
Single Observation ◽  
Half Century ◽  
Climate Monitoring ◽  
System Requirements ◽  
Incomplete Sampling

Abstract Using a reanalysis of the climate of the past half century as a model of temperature variations over the next half century, tests of various data collection protocols are made to develop recommendations for observing system requirements for monitoring upper-air temperature. The analysis focuses on accurately estimating monthly climatic data (specifically, monthly average temperature and its standard deviation) and multidecadal trends in monthly temperatures at specified locations, from the surface to 30 hPa. It does not address upper-air network size or station location issues. The effects of reducing the precision of temperature data, incomplete sampling of the diurnal cycle, incomplete sampling of the days of the month, imperfect long-term stability of the observations, and changes in observation schedule are assessed. To ensure accurate monthly climate statistics, observations with at least 0.5-K precision, made at least twice daily, at least once every two or three days are sufficient. Using these same criteria, and maintaining long-term measurement stability to within 0.25 (0.1) K, for periods of 20 to 50 yr, errors in trend estimates can be avoided in at least 90% (95%) of cases. In practical terms, this requires no more than one intervention (e.g., instrument change) over the period of record, and its effect must be to change the measurement bias by no more than 0.25 (0.1) K. The effect of the first intervention dominates the effects of subsequent, uncorrelated interventions. Changes in observation schedule also affect trend estimates. Reducing the number of observations per day, or changing the timing of a single observation per day, has a greater potential to produce errors in trends than reducing the number of days per month on which observations are made. These findings depend on the validity of using reanalysis data to approximate the statistical nature of future climate variations, and on the statistical tests employed. However, the results are based on conservative assumptions, so that adopting observing system requirements based on this analysis should result in a data archive that will meet climate monitoring needs over the next 50 yr.

The Risk Premium on Ordinary Shares

1995 ◽  
Vol 1 (2) ◽  
pp. 251-330 ◽  
Author(s):  
A.D. Wilkie
Keyword(s):  
Risk Premium ◽  
Geometric Mean ◽  
Arithmetic Mean ◽  
Short Term ◽  
Arithmetic Means ◽  
Price Inflation ◽  
Geometric Means ◽  
True Model ◽  
The Difference

ABSTRACTThe risk premium on ordinary shares is investigated, by studying the total returns on ordinary shares, and on both long-term and short-term fixed-interest investments over the period 1919 to 1994, and by analysing the various components of that return. The total returns on ordinary shares exceeded those on fixed-interest investments by over 5% p.a. on a geometric mean basis and by over 7% p.a. on an arithmetic mean basis, but it is argued that these figures are misleading, because most of the difference can be accounted for by the fact that price inflation turned out to be about 4.5% p.a. over the period, whereas investors had been expecting zero inflation.Quotations from contemporary authors are brought forward to demonstrate what contemporary attitudes were. Simulations are used along with the Wilkie stochastic asset model to show what the results would be if investors make various assumptions about the future, but the true model turns out to be different from what they expected. The differences between geometric means of the data and arithmetic means are shown to correspond to differences between using medians or means of the distribution of future returns, and it is suggested that, for discounting purposes, medians are the better measure.

The Wilkie Model for Retail Price Inflation Revisited

1998 ◽  
Vol 4 (3) ◽  
pp. 637-652 ◽  
Author(s):  
W.S. Chan ◽  
S. Wang
Keyword(s):  
Time Series ◽  
Original Model ◽  
Retail Price ◽  
Investment Model ◽  
Outlier Analysis ◽  
Residual Distribution ◽  
Data Set ◽  
Price Inflation ◽  
Arch Models ◽  
First Order

ABSTRACTA first order autoregressive model was proposed in Wilkie (1995) for the retail price inflation series as a part of his stochastic investment model. In this paper we apply time series outlier analysis to the data set and a revised model is derived. It significantly alleviates the problem of leptokurtic and positive skewed residual distribution as found in the original model. Finally, ARCH models for the original series and the outlier-adjusted data are also considered.

Chapter I. The Economy in 1978

1979 ◽  
Vol 87 ◽  
pp. 13-24
Keyword(s):  
Fiscal Policy ◽  
Private Consumption ◽  
Public Expenditure ◽  
Labour Force ◽  
Retail Price ◽  
Capital Expenditures ◽  
Public Authorities ◽  
Price Inflation ◽  
The Public

The overall pattern of changes in real expenditure and output was markedly different in 1978 from that of 1977 (see chart 1). In 1977, largely because of the undertakings given in the Letter of Intent to the IMF of December 1976, fiscal policy was deliberately restrictive. The stance of fiscal policy was made harsher still by the public expenditure shortfall produced by the operation of the relatively unfamiliar cash limits. There was a fairly small fall in public authorities' current spending and much larger falls in capital expenditures. Private consumption, too, fell as stages II and III of the pay policy operated. Trade to 6 per cent of the labour force. Retail price inflation did, however, fall fractionally from 16.5 per cent in 1976 to 15.9 per cent in 1977 (and to 13 per cent through the year).

scholarly journals Bioeconomic Approach for Assessing Status of Trawl Fishery in the Straits of Malacca

2021 ◽  
Vol 34 (4) ◽  
Author(s):  
HOONG SANG WONG ◽  
◽  
CHEN CHEN YONG ◽  
AZMAH OTHMAN
Keyword(s):  
Fishery Management ◽  
Statistical Tests ◽  
Fishing Effort ◽  
Current Status ◽  
Fish Stock ◽  
Base Case ◽  
Current Effort ◽  
Price Inflation ◽  
Trawl Fishery ◽  
Straits Of Malacca

The Straits of Malacca provides half of Malaysia’s total marine fish and seafood supply. Due to depleted fish stock, the Malaysian Government has established a comprehensive legal framework to reduce overfishing in the Straits over the last five decades. However, there are limited scientific studies on the current status of stock recovery. This paper aims to use bioeconomic approach to determine the current trawl fishery status in the Straits. Various statistical tests showed that the Clarke-Yoshimoto-Pooley model was better than the Schnute model in predicting and thus used to estimate the crucial bioeconomic parameters. The current yield and standardised effort of 239,692 tonnes and 931,692 standard fishing days were very close to the estimated biological maximum sustainable yield (239,915 tonnes) and above 18 % of the standardised effort (763,649 standard fishing days) to achieve it. The maximum economic yield was estimated at 201,542 tonnes while the corresponding standardised effort was 396,799 standard fishing days indicating serious economic overfishing in the Straits. If the current effort can be reduced by 57 %, fish biomass and economic rent will increase by 97 % and 835 %, respectively. A price sensitivity analysis predicted that demand-pull fish price inflation could exacerbate the overfishing problem, particularly under unrestrained environment. A 50 % increase in price could lead to a 132 % increase in fishing effort from the base case. The findings of this paper provide valuable insights for fishery managers to refine their existing fishery management program to achieve sustainable fishery for the future.

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