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Foreword 



This set of 12 volumes on the Major Statistical Series of the U.S. Department of 

 Agriculture (Agriculture Handbook No. 671) is the second revision that supersedes the 

 original volumes published during 1957-60. The first revision was completed in 1972. 



Our goal for this handbook remains essentially unchanged. We hope to help govern- 

 ment, university, private sector, and other users become better acquainted with the 

 concepts and data underlying the Department's statistical series. We believe this 

 handbook will benefit new users as well as those already familiar with the Depart- 

 ment's statistics. If you find it valuable in improving your knowledge of what the 

 various data series measure and how appropriate they may be for specific uses, we will 

 have largely succeeded. 



The challenge for our statistics is to reflect events in the agricultural sector and rural 

 areas as they are, insofar as possible, and in this way contribute to public under- 

 standing. Because much has changed in the economics of rural areas and the food and 

 fiber system since the last revision, we have adopted some new procedures. Thus, 

 although the revised handbook describes several established series essentially as they 

 were in the two earlier handbooks, it also notes changes in ongoing series, describes 

 new series, and identifies some series that are no longer published. 



Your interest in the Department of Agriculture's statistical series is important. We 

 welcome comments on either these handbook volumes or the series they describe. 



CHARLES E. CAUDILL yJOHN E. LEE, JR. 



Administrator, ' Administrator, 



National Agricultural Economic Research Service 

 Statistics Service 



