Statistical Analysis

By Edmund E. Day, 'OS, Professor of Economics and Dean of the School of Business Administration, Univer- sity of Michigan. (The Macmillan Company, 1925, Pp, 459.)

In recent years, recognition of the value of statistical methods in studying economic and business problems has become general. Business organizations have created statistical departments. Most schools of business administration and departments of economics offer courses of instruction in statistical methods. In fact, an introductory course in statistics is often required of advanced students in either of these fields.

Teachers of such courses in applied statistical methods have been seriously handicapped by the lack of satisfactory text books. This need was so apparent to publishers that 1924 and 1925 may become historic as the years of the great flood of statistics texts. The books which have just descended in such quantity differ widely in point of view, for the subject is many sided. Some of the authors emphasize its mathematical aspects; others, graphical methods; still others have attempted to cover the whole subject with equal emphasis.

In his book, Dean Day discusses only briefly methods of collection and tabulation for, in his opinion, the great majority of students of statistical methods, as applied to economics and business administration, are interested in the technique of collection or tabulation only in so far as they affect the subsequent analysis of data. He has focussed attention upon the problems of analysis. In fact, he states that in more extended form the title of the volume might well be "The Logic of Statistical Analysis," for his purpose is to make clear the logic of statistical procedure with particular stress on the methods Used in analysis. In accordance with this purpose, the tone of the book is philosophical rather than mathematical. No training in advanced mathematics is assumed.

Professor Day's experience as a teacher resulted in an arrangement of material which will be very convenient for class room instruction. Variables, classification, analysis of frequency distribution, correlation, analysis of spatial series and of time series, and index numbers are taken up in the order named. He closes with a very valuable chapter dealing with the significance of statistical results. Correction methods, rules for tabulation, tables of squares, logarithms, etc., appear in appendices.

The graphical method has not been neglected. It is considered throughout the book under each subject rather than in a chapter by itself, in the hope that this rather unconventional treatment will be instrumental in promoting a more logical use of these convenient devices in the various phases of statistical investigation to which they can be adapted. More than a hundred tables and almost as many charts have been included to illustrate principles discussed by the author.

One-third of the book is devoted to the analysis of time series, in which field statistical technique has most recently been making rapid strides. This subject has been admirably handled by the author, much to the satisfaction of economists and business statisticians, for it is with time series that most of their problems have to do.

Many perons who use the statistical method forget the limitations of this valuable too' and feel that it provides the conclusive answer to all questions. That Dean Day is not of this group is clearly shown in his final chapter, already mentioned, in which he says:

"In social sciences, the impossibility—or, at best, very limited possibility—of experiment has been repeatedly noted. The so-called law of the single variable cannot apply. The observer of economic and business phenomena must take the records as they stand, registering as they do in each case the operation of numerous factors. He must then deal with the records on the assumption of multiple causation, and through statistical analysis gain as much insight as possible into the nature of the causes that are at work.

"The fundamental distinction between experimental and statistical methods is that experimental methods are manipulative and statistical methods are descriptive."

In closing, he points out that statistical results may create presumptions in favor of certain conclusions, but that they almost always leave room for some divergence of opinion, Statistical results are rarely, if ever, conclusive.

"Exercise of judgment based upon wide familiarity with the situation, and great caution in the statement of conclusions from the data, are the beginning of wisdom in statistical work."

Though the book is intended primarily for students wishing to gain a first acquaintance with the subject through formal class room instruction, the treatment is comprehensive, and more advanced students will find great value in its carefully stated definitions and principles.

"Discharge Records of North Carolina Streams 1889-1923" by Thorndike Saville '14 and G. Wallace Smith has been published as bulletin number 34, North Carolina Department of Conservation and Development. This publication consists of over four-hundred pages.

"Modern Cod Liver Oil" by Arthur D. Holmes, Ph. D. '06 has been reprinted from the January 15th issue of the Medical Searchlight, Philadelphia.

Houghton Mifflin and Company have published "Detours (Passable but Unsafe)" by Phillip S. Marden '94. This volume of essays will be reviewed in a future issue of the magazine.

Hastings Lyon '05 formerly on the Tuck School faculty is the author of a book "Investment." This will be reviewed later.

McBride and Company have just published a novel "Topper" by Thorne Smith. (James Thorne Smith, Jr. '14.)

"The Border Missions of General George Mathews" by Isaac J. Cox '96 has been reprinted from the Mississippi Valley HistoricalReview for December 1925.

Dr. Charles H. Richardson '92 head of the Department of Mineralogy at Syracuse is the author of a new book "Mineralogy of Kentucky" published by the KentuckyGeological Survey. This is the fourth book which Dr. Richardson has prepared for the Kentucky Geological Survey. The others are: "Building Stones of Kentucky"; "Road Material for Kentucky"; "Glass Sands of Kentucky". A fifth volume by Professor Richardson entitled "The Molding Sands and Cement Materials of Kentucky" has been prepared and will be published by the KentuckyGeological Survey this next summer.