SIC stands for standard industrial classification. The system was developed in the 1930s by the U.S. federal government to promote uniformity and comparability in the presentation of economic statistical data. SIC codes consist of four digits, with the first two digits identifying the major industry group, the third identifying the industry group and the fourth the industry. Because of economic growth and expansion, by the 1990s it was decided that a new system was needed with more digits for more specific classifications. The six-digit North American Industry classification System was developed by 1997. Converting SIC codes to new codes is a complex process.
Develop your numbering system by assigning numbers to different major industry groups, for example agriculture, mining, utilities, etc.
Determine your objective for converting SIC codes into new codes, that is, what you are trying to accomplish. Bear in mind that there are different organizations that develop code systems and gather data, for example, issuers of credit cards track transactions from commercial customers based on the MCC. There is no need to reinvent the wheel, so if what you are trying to accomplish is already being done elsewhere, borrow from and/or utilize those other sources.
Develop your numbering system for divisions within the major industry group, for example within agriculture divisions would include agricultural production--crops and agricultural production--livestock and agriculture services, etc.
Gain an understanding of the SIC code system. Learn what the codes stand for and how they are used to gather economic data. You may also want to study other code systems like the NAICS and the Merchant Classification Code system (MCC).
In order to make your code system meaningful with regards to time series data going back to past years you will need to develop a conversion table linking SIC codes to your new code system. This will allow economic data from the SIC code system to be used with the new code system. However, the new code system may have divisions that were not recognized by the SIC code system. In these cases data may have to be estimated based other related data.
Develop your numbering system for divisions within the divisions of the major industry groups, for example divisions within agricultural production--crops would include wheat, rice, soybeans etc. Repeat this step to carry the numbering system out as far as necessary to accomplish your objective.
评论