Arthur C. Nielsen Jr., who transformed the company his father founded in 1923 into an international leader in market research, helping to make its name synonymous with television ratings, died on Monday in Winnetka, Ill.  He was 92.

Mr. Nielsen recognized the potential to use such calculations in the family business, which at that point had gained most of its profit from an index that measured and tracked sales of items in food and drug stores. The company, one of the first ever to offer market research, also began to measure radio stations’ audience size in 1936.  The most visible expansion of the Nielsen business took place in the media measurement division.  Nielsen fought to retain its place — critics have long labeled it a monopoly — over the measurement of television ratings, beating back the challenges of several potential rivals. As cable television began vastly expanding the number of networks needing national measurement, Nielsen was positioned to provide the numbers each of those channels needed to sell time to advertisers.

Mr. Nielsen stepped down from active leadership in 1983 and became chairman emeritus.  The following year he engineered the sale of A. C. Nielsen to the Dun & Bradstreet Corporation for $1.3 billion in stock.

The company was later acquired by the Dutch publishing company VNU.  It is now an independent company, Nielsen Holdings N.V., which is publicly traded under the symbol NLSN.

Source:  New York Times