The Research On Ratio Estimators Of Sampling Survey Of Road Freight Transportation Volume

With the development of the road transportation industry,the state administration has paid more and more attention to the road transportation volume.By virtue of its less cost,more scope application and higher time-effect,sampling survey has become the first choice for the survey of road transportation volume.Sampling design and sampling estimation are two important stages in the sample survey.At present,there are many studies on the method of road freight transportation sampling,but the research on the estimation is less.Estimators include simple estimators and complex estimators.Simple estimators only use research variables to estimate target population.The complex estimates include the ratio estimators and the regression estimators.On the basis of using sample information of research variables,it makes full use of the information of the auxiliary variables which are highly correlated with the research variables.Therefore,this paper selects the ratio estimators in the complex estimators as the research object,which is of great significance for improving the accuracy of road freight transportation sampling survey.First of all,this paper starts with the research status of ratio estimators of road freight transportation volume sampling survey,and puts forward the necessity and importance of research on the estimators of road freight transportation volume sampling survey.Secondly,the paper expounds relevant theories about the ratio estimator of the road transportation volume sampling survey.Then,on the basis of introducing the variation coefficient,kurtosis coefficient and correlation coefficient of auxiliary variables,a new type of ratio estimator is defined in simple random sampling and stratified sampling.And the mean square error of these estimators is derived.Meanwhile,the new ratio estimator is compared with the simple estimator and the traditional ratio estimator under the same sampling investigation method.In addition,the empirical analysis is carried out by using the data of Xi'an in Shaanxi province of small sample survey of highway and waterway in 2015.The results show that the efficiency of these proposed ratio estimator is better than the simple estimator and the ratio estimator in case of the same sampling investigation method.It is shown that the accuracy of ratio estimation can be effectively improved by introducing coefficient of variation,kurtosis coefficient and correlation coefficient.The empirical analysis shows that the new ratio estimator constructed with marked tonnage as an auxiliary variable can improve the precision of sampling estimation of road freight transportation volume.