Tax compliance and social desirability bias of taxpayers: experimental evidence from Indonesia

Identifying taxpayers who engage in noncompliant behaviour is crucial for tax authorities to determine appropriate taxation schemes. However, because taxpayers have an incentive to conceal their true income, it is difficult for tax authorities to uncover such behaviour (social desirability bias). Our study mitigates the bias in responses to sensitive questions by employing the list experiment technique, which allows us to identify the characteristics of taxpayers who engage in tax evasion. Using a dataset obtained from a tax office in Jakarta, Indonesia, we conducted a computer-assisted telephone interviewing survey in 2019. Our results revealed that 13% of the taxpayers, old, male, corporate employees, and members of a certain ethnic group had reported lower income than their true income on their tax returns. These findings suggest that our research design can be a useful tool for understanding tax evasion and for developing effective taxation schemes that promote tax compliance.

Optimizing Replaced Nozzle Diameter of Abrasive Blasting Systems Using Experiment Technique Design

The blasting technique has been broadly utilized to prepare new surfaces for painting, engraving, etc., in industry. In fact, the minimization of the cleaning cost system is essential. However, the knowledge of this technique in terms of optimization has been poor so far. The aim of this study is to find the optimum replaced boron carbide nozzle diameter for the abrasive blasting system. The basis of the study is to find the replaced nozzle diameter to minimize the cost of the blasting system. Seven main parameters are adopted for examining their influences on the response and the optimum replaced nozzle diameter. The design of experiment (DOE) technique is utilized by using Minitab@19. The results reveal that the initial nozzle diameter has the strongest impact on the optimum replaced nozzle diameter. Furthermore, the proposed regression model has been found to be entirely insistent to the experiments. The utilization of this model can provide an effective way to simplify the calculation of the optimum initial nozzle diameter for boron carbide.

The Influence of Quantum Teaching Method and Cooperative Integrated Reading and Composition Method on Descriptive Writing Skill of Elementary Student

Thisresearchaimedatfindingouttheinfluenceofquantumteaching(QT)methodand cooperative integrated reading composition (CIRC) method on elementary students’ descriptive writing skill. This research used quantitative method with quasi experiment technique. This research used non-equivalent control group pretest-postest design. The population in this research was all the students at grade 5 in SD Muhammadiyah 1 Alternatif Kota Magelang. The data analysis techniques used in this research were paired sample t-test and analysis of variance (anova). The result showed that: (1) there was positive influence on the use of quantum teaching (QT) method on descriptive writing skill of grade 5 students in SD Muhammadiyah 1 Alternatif Kota Magelang, (2) there was positive influence on the use of cooperative integrated reading composition (CIRC) method on descriptive writing skill at grade 5 students in SD Muhammadiyah 1 Alternatif Kota Magelang, and (3) there was different influence on the use of quantum teaching(QT)methodandcooperativeintegratedreading(CIRC)methodondescriptive writing skill at grade 5 students in SD Muhammadiyah 1 Alternatif Kota Magelang.

Statistical analysis of the item-count technique using Stata

In this article, I review recent developments of the item-count technique (also known as the unmatched-count or list-experiment technique) and introduce a new package, kict, for statistical analysis of the item-count data. This package contains four commands: kict deff performs a diagnostic test to detect the violation of an assumption underlying the item-count technique. kict ls and kict ml perform least-squares estimation and maximum likelihood estimation, respectively. Each encompasses a number of estimators, offering great flexibility for data analysis. kict pfci is a postestimation command for producing confidence intervals with better coverage based on profile likelihood. The development of the item-count technique is still ongoing. I will continue to update the kict package accordingly.

Optimization of a Centrifugal Compressor Using the Design of Experiment Technique

Centrifugal compressor performance is affected by many parameters, optimization of which can lead to superior designs. Recognizing the most important parameters affecting performance helps to reduce the optimization process cost. Of the compressor components, the impeller plays the most important role in compressor performance, hence the design parameters affecting this component were considered. A turbocharger centrifugal compressor with vaneless diffuser was studied and the parameters investigated included meridional geometry, rotor blade angle distribution and start location of the main blades and splitters. The diffuser shape was captured as part of the meridional geometry. Applying a novel approach to the problem, full factorial analysis was used to investigate the most effective parameters. The Response Surface Method was then implemented to construct the surrogate models and to recognize the best points over a design space created as based on the Box-Behnken methodology. The results highlighted the factors that affected impeller performance the most. Using the Design of Experiment technique, the model which optimized both efficiency and pressure ratio simultaneously delivered a design with 3% and 11% improvement in each respectively in comparison to the initial impeller at the design point. Importantly, this was not at the expense of sacrificing range, of critical concern in compressor design.

Experimental studies of the E01 leaky wave characteristics in a round dielectric rod

Excitation experiment technique of the E01 leaky wave in a round open dielectric waveguide is given. Experimental research results of the E01 leaky wave characteristics of a round open dielectric waveguide are presented.