Answer to Question #190002 in Economics for Habib

Question

what is difference between the population and sample regression function. Is this a distinction without difference?

Answer 1

With the sampling method, a relatively small part of the entire studied population is subjected to survey (usually up to 5-10%, less often up to 15-25%). In this case, the statistical population to be studied, from which a part of the units is selected, is called the general population. Selected from the general population, some part of the units that are being surveyed is called a sample population or simply a sample. The sample can be:) actually random; ) mechanical; ) typical; ) serial; ) combined. Properly random sampling consists in the fact that the sample population is formed as a result of a random (unintentional) selection of individual units from the general population. In this case, the number of units selected for the sample is usually determined based on the accepted proportion of the sample. Mechanical sampling consists in the fact that the selection of units in the sample population is made from the general population, divided into equal intervals (groups). Moreover, the size of the interval in the general population is equal to the reciprocal of the proportion of the sample. An important feature of mechanical sampling is that the formation of a sample population can be carried out without resorting to compiling lists. In practice, the order in which the units of the general population are actually placed is often used. For example, the sequence of exit of finished products from a conveyor or production line, the order of placing units of a batch of goods during storage, transportation, sale, etc. In a typical sample, the general population is first divided into homogeneous typical groups. Then, from each typical group, by proper random or mechanical sampling, an individual selection of units is made into the sample population. Typical sampling is usually used when studying complex statistical populations. For example, in a sample survey of labor productivity of trade workers, consisting of separate groups according to qualifications. An important feature of a typical sample is that it gives more accurate results compared to other methods of selecting units in a sample population. If the sample does not include individual units of the population, but the whole series, such a sample is called a serial sample. Serial sampling is rarely used because gives a high sampling error. Combined sampling involves the use of several sampling methods. You can combine, for example, serial and random sampling. In this case, after dividing the general population into series (groups) and selecting the required number of series, a random sample of units in the series is made. You can combine typical and serial sampling.