scholarly journals Integration of Nonprobability and Probability Samples via Survey Weights

2021 ◽  
Vol 10 (6) ◽  
pp. 5
Author(s):  
Balgobin Nandram ◽  
Jai Won Choi ◽  
Yang Liu

Probability sample encounters the problems of increasing cost and nonresponse. The cost has rapidly been increasing in executing a large probability sample survey, and, for some surveys, response rate can be below the 10 percent level. Therefore, statisticians seek some alternative methods. One of them is to use a large nonprobability sample (S_1 ) supplemented by a small probability sample (S_2 ). Both samples are taken from the same population and they include common covariates, and a third sample (S_3 ) is created by combining these two samples; S_1  can be biased and S_2  may have large sample variance. These two problems are reduced by survey weights and combining the two samples. Although S_2  is a small sample, it provides good properties of unbiasedness in estimation and of survey weights. With these known weights, we obtain adjusted sample weights (ASW), and create a sample model from a finite population model. We fit the sample model to obtain its parameters and generate values from the population model. Similarly, we repeat these processes for other two samples, S_1  and S_3  and for different statistical methods. We show reduced biases of the finite population means and reduced variances.as the combined sample size becomes large. We analyze sample data to show the reduction of these two errors.

Author(s):  
A. I. Belousov

The main objective of this paper is to prove a theorem according to which a method of successive elimination of unknowns in the solution of systems of linear equations in the semi-rings with iteration gives the really smallest solution of the system. The proof is based on the graph interpretation of the system and establishes a relationship between the method of sequential elimination of unknowns and the method for calculating a cost matrix of a labeled oriented graph using the method of sequential calculation of cost matrices following the paths of increasing ranks. Along with that, and in terms of preparing for the proof of the main theorem, we consider the following important properties of the closed semi-rings and semi-rings with iteration.We prove the properties of an infinite sum (a supremum of the sequence in natural ordering of an idempotent semi-ring). In particular, the proof of the continuity of the addition operation is much simpler than in the known issues, which is the basis for the well-known algorithm for solving a linear equation in a semi-ring with iteration.Next, we prove a theorem on the closeness of semi-rings with iteration with respect to solutions of the systems of linear equations. We also give a detailed proof of the theorem of the cost matrix of an oriented graph labeled above a semi-ring as an iteration of the matrix of arc labels.The concept of an automaton over a semi-ring is introduced, which, unlike the usual labeled oriented graph, has a distinguished "final" vertex with a zero out-degree.All of the foregoing provides a basis for the proof of the main theorem, in which the concept of an automaton over a semi-ring plays the main role.The article's results are scientifically and methodologically valuable. The proposed proof of the main theorem allows us to relate two alternative methods for calculating the cost matrix of a labeled oriented graph, and the proposed proofs of already known statements can be useful in presenting the elements of the theory of semi-rings that plays an important role in mathematical studies of students majoring in software technologies and theoretical computer science.


2019 ◽  
Vol 11 (1) ◽  
pp. 156-173
Author(s):  
Spenser Robinson ◽  
A.J. Singh

This paper shows Leadership in Energy and Environmental Design (LEED) certified hospitality properties exhibit increased expenses and earn lower net operating income (NOI) than non-certified buildings. ENERGY STAR certified properties demonstrate lower overall expenses than non-certified buildings with statistically neutral NOI effects. Using a custom sample of all green buildings and their competitive data set as of 2013 provided by Smith Travel Research (STR), the paper documents potential reasons for this result including increased operational expenses, potential confusion with certified and registered LEED projects in the data, and qualitative input. The qualitative input comes from a small sample survey of five industry professionals. The paper provides one of the only analyses on operating efficiencies with LEED and ENERGY STAR hospitality properties.


2021 ◽  
pp. 097370302110296
Author(s):  
Soumyajit Chakraborty ◽  
Alok K. Bohara

Being from backward castes, classes and Muslims in India has an economic cost associated with the nature of institutional discrimination. Using the 2011–2012 National Sample Survey data, this study identifies that caste and religion still rule the modern Indian labour market. We find that discrimination is evident in the socio-religious earnings gaps. While the parametric decompositions suggest that most of these gaps are due to differential human capital endowment, the nonparametric method almost evenly attributes inequality to discrimination and endowment. The results presented in this study suggest that discrimination against Scheduled Castes and Scheduled Tribes, Muslims and Other Backward Classes should be included in policy designs to promote equity in the Indian labour market.


SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A177-A177
Author(s):  
Jaejin An ◽  
Dennis Hwang ◽  
Jiaxiao Shi ◽  
Amy Sawyer ◽  
Aiyu Chen ◽  
...  

Abstract Introduction Trial-based tele-obstructive sleep apnea (OSA) cost-effectiveness analyses have often been inconclusive due to small sample sizes and short follow-up. In this study, we report the cost-effectiveness of Tele-OSA using a larger sample from a 3-month trial that was augmented with 2.75 additional years of epidemiologic follow-up. Methods The Tele-OSA study was a 3-month randomized trial conducted in Kaiser Permanente Southern California that demonstrated improved adherence in patients receiving automated feedback messaging regarding their positive airway pressure (PAP) use when compared to usual care. At the end of the 3 months, participants in the intervention group pseudo-randomly either stopped or continued receiving messaging. This analysis included those participants who had moderate-severe OSA (Apnea Hypopnea Index >=15) and compared the cost-effectiveness of 3 groups: 1) no messaging, 2) messaging for 3 months only, and 3) messaging for 3 years. Costs were derived by multiplying medical service use from electronic medical records times costs from Federal fee schedules. Effects were average nightly hours of PAP use. We report the incremental cost per incremental hour of PAP use as well as the fraction acceptable. Results We included 256 patients with moderate-severe OSA (Group 1, n=132; Group 2, n=79; Group 3, n=45). Group 2, which received the intervention for 3 months only, had the highest costs and fewest hours of use and was dominated by the other two groups. Average 1-year costs for groups 1 and 3 were $6035 (SE, $477) and $6154 (SE, $575), respectively; average nightly hours of PAP use were 3.07 (SE, 0.23) and 4.09 (SE, 0.42). Compared to no messaging, messaging for 3 years had an incremental cost ($119, p=0.86) per incremental hour of use (1.02, p=0.03) of $117. For a willingness-to-pay (WTP) of $500 per year ($1.37/night), 3-year messaging has a 70% chance of being acceptable. Conclusion Long-term Tele-OSA messaging was more effective than no messaging for PAP use outcomes but also highly likely cost-effective with an acceptable willingness-to-pay threshold. Epidemiologic evidence suggests that this greater use will yield both clinical and additional economic benefits. Support (if any) Tele-OSA study was supported by the AASM Foundation SRA Grant #: 104-SR-13


2014 ◽  
Vol 143 (7) ◽  
pp. 1500-1510 ◽  
Author(s):  
P. PRAH ◽  
A. J. COPAS ◽  
C. H. MERCER ◽  
A. NARDONE ◽  
A. M. JOHNSON

SUMMARYPatterns of sexual mixing are major determinants of sexually transmitted infection (STI) transmission, in particular the extent to which high-risk populations mix with low-risk populations. However, patterns of mixing in the general population are poorly understood. We analysed data from a national probability sample survey of households, the Health Survey for England 2010. A total of 943 heterosexual couples living together, where at least one partner was aged between 16–44 years, were included. We used correlation coefficients to measure the strength of similarities between partners with respect to demographic characteristics, general health, health behaviours and sexual history. Males were on average 2 years older than their female partners, although this age difference ranged from a median of 0 years in men aged 16–24 years to a median of 2 years in men aged 35–44 years. A positive correlation between partners was found for all demographic characteristics. With respect to general health and health behaviours, a strongly positive correlation was found between men and women in reporting alcohol consumption at ⩾3 days a week and smoking. Men typically reported greater numbers of sexual partners than their female partner, although men and women with more partners were more likely to mix with each other. We have been able to elucidate the patterns of sexual mixing between men and women living together in England. Mixing based on demographic characteristics was more assortative than sexual characteristics. These data can better inform mathematical models of STI transmission.


2021 ◽  
Author(s):  
Andrew Briggs ◽  
Beth Wehler ◽  
Jennifer G. Gaultney ◽  
Alex Upton ◽  
Antoine Italiano ◽  
...  

2018 ◽  
Vol 10 (11) ◽  
pp. 3937 ◽  
Author(s):  
Sahar Bouaddi ◽  
Aránzazu Fernández-García ◽  
Chris Sansom ◽  
Jon Sarasua ◽  
Fabian Wolfertstetter ◽  
...  

The severe soiling of reflectors deployed in arid and semi arid locations decreases their reflectance and drives down the yield of the concentrating solar power (CSP) plants. To alleviate this issue, various sets of methods are available. The operation and maintenance (O&M) staff should opt for sustainable cleaning methods that are safe and environmentally friendly. To restore high reflectance, the cleaning vehicles of CSP plants must adapt to the constraints of each technology and to the layout of reflectors in the solar field. Water based methods are currently the most commonly used in CSP plants but they are not sustainable due to water scarcity and high soiling rates. The recovery and reuse of washing water can compensate for these methods and make them a more reasonable option for mediterranean and desert environments. Dry methods, on the other hand, are gaining more attraction as they are more suitable for desert regions. Some of these methods rely on ultrasonic wave or vibration for detaching the dust bonding from the reflectors surface, while other methods, known as preventive methods, focus on reducing the soiling by modifying the reflectors surface and incorporating self cleaning features using special coatings. Since the CSP plants operators aim to achieve the highest profit by minimizing the cost of cleaning while maintaining a high reflectance, optimizing the cleaning parameters and strategies is of great interest. This work presents the conventional water-based methods that are currently used in CSP plants in addition to sustainable alternative methods for dust removal and soiling prevention. Also, the cleaning effectiveness, the environmental impacts and the economic aspects of each technology are discussed.


2014 ◽  
Vol 30 (3) ◽  
pp. 325-332 ◽  
Author(s):  
Hema Mistry

Objectives: In economic evaluations of healthcare technologies, situations arise where data are not randomized and numbers are small. For this reason, obtaining reliable cost estimates of such interventions may be difficult. This study explores two approaches in obtaining cost estimates for pregnant women screened for a fetal cardiac anomaly.Methods: Two methods to reduce selection bias in health care: regression analyses and propensity scoring methods were applied to the total mean costs of pregnancy for women who received specialist cardiac advice by means of two referral modes: telemedicine and direct referral.Results: The observed total mean costs of pregnancy were higher for the telemedicine group than the direct referral group (4,918 versus 4,311 GBP). The regression model found that referral mode was not a significant predictor of costs and the cost difference between the two groups was reduced from 607 to 94 GBP. After applying the various propensity score methods, the groups were balanced in terms of sizes and compositions; and again the cost differences between the two groups were smaller ranging from -62 (matching “by hand”) to 333 GBP (kernel matching).Conclusions: Regression analyses and propensity scoring methods applied to the dataset may have increased the homogeneity and reduced the variance in the adjusted costs; that is, these methods have allowed the observed selection bias to be reduced. I believe that propensity scoring methods worked better for this dataset, because after matching the two groups were similar in terms of background characteristics and the adjusted cost differences were smaller.


Author(s):  
S. E. Jonah ◽  
B. G. Shettima ◽  
A. S. S. Umar ◽  
E. Timothy

Aims: Sesame productions are constantly bedeviled with menace because of inadequate supply of quality seed, extension services, credit facilities, presence of inefficiencies among others. The capacity of sesame producers to accept new innovation and achieve sustained production relies upon the level of profit efficiency, generally dictated by variable input and output prices including the cost of fixed factors of production. Physical profitability contemplations such technical, allocative and economic efficiency are significant in improving production proficiency but profit efficiency will result to higher profit to sesame farmers. This paper examined the profit efficiency of sesame production in Yobe State, Nigeria. Research Methods: Multistage sampling procedure is utilized to choose the farmers. A structured questionnaire is administered to 180 respondents spread across 12 Local Government Areas to acquired essential information. Descriptive statistics used includes mean, frequency and percentage. The inferential statistic used is stochastic translog profit function. Findings: The result of levels of profit efficiency shows the mean profit efficiency of 0.8828. The result of the translog profit function indicates the sigma square to be 0.249 and variance of 0.909. All the cost variables has negative coefficients and significant at one percent level except for cost of farmlands. The inefficiency variables levels of education, Access to Extension Services, Access to credits among others reduce inefficiency while off-farm income and access to market information increase inefficiency. Conclusion: It can be concluded that inefficiency exist in the utilization of resources. All the input cost variable decreases profit efficiency and all the socioeconomic characteristics decreases profit inefficiency with the exception of, off-farm income and access to market information which were found to increase profit inefficiency.


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