The greater distance between seller and purchaser, the more important the choice of the means of transportation and the particular carrier. Railroads, airlines, waterways, and most long-distance trucking firms are defined as common carriers. As a general rule, those with the most education had the highest salaries in their field. Qualified persons usually begin as trainees, purchasing clerks, expediters, junior buyers, or assistant buyers. Retail and wholesale firms prefer to hire applicants who are familiar with the merchandise they sell as well as with wholesaling and retailing practices.
Most employers use a combination of methods.
Educational requirements tend to vary with the size of the organization. Large stores and distributors, especially those in wholesale and retail trade, prefer applicants who have completed a bachelor's degree program with a business emphasis. Many manufacturing firms prefer applicants with a bachelor's or master's degree in business, economics, or technical training such as engineering or one of the applied sciences and tend to put a greater emphasis on formal training. Regardless of academic preparation, new employees must learn the specifics of their employers' business. Training periods vary in length, with most lasting 1 to 5 years.