MONTHLY data for the building and construction industries available for the period since the War make possible a fairly satisfactory measure of the cyclical fluctuations in building activity. In an earlier issue of this REVIEW, a detailed analysis of building statistics for the United States was presented and certain important conclusions were drawn concerning the general character of fluctuations in the building industry.' The following pages are devoted to a brief description of the post-war cyclical fluctuations of building activity and to discussion of the data, methods, and statistical background of our adjusted indexes of building and real estate activity.

extent and direction of the month-to-month fluctuations were substantially accurate, the general level of the index was somewhat too low. The current revision was undertaken therefore in order to correct this discrepancy in level and, at the same time, to improve the several industry indexes. Chart i presents the revised mining index, monthly, for the period since August 1922, in comparison with the unrevised index which is shown for the interval since January 19I9. The tie-on between the old and the new index was made in August 1922, the closing month of the prolonged coal strike in the bituminous coal and anthracite fields. The two indexes were then practically coincident. The higher level of the revised index is accounted for in the main by revisions in the normal lines for output of anthracite and bituminous coal and for shipments of iron ore. The technique of the analysis has in general been similar to that of the revision of the index of the volume of manufacture which was discussed in detail in the May 1929 REVIEW. The revised index, like the old, is a weighted arithmetic average of relatives, the weights being based upon average values of the minerals over a period of years. The fuels and metals group indexes have been retained and are shown in graphic form on Chart 2. The fluctuations in the

I N September I92I, the Harvard Economic Service first published its Unadjusted Monthly Index of the Volume of Manufacture. This unadjusted index was published currently until the following March when the adjusted monthly index was first presented. It was not until August I922, however (shortly after preliminary data from the I9I9 Census of Manufactures became available), that the index appeared as a combination of the three subordinate indexes registering fluctuations in the physical volume of output of (I) basic materials, (2) equipment and vehicles, and (3) consumption

FROM the standpoint of the physical volume of production, the year I926 was one of extraordinary growth. Actual output of both manufacture and mining established new high records for all time and agricultural production, the largest in the past 6 years, has been exceeded only in 1920 (Tables A and H). In each of these major lines of activity, the increase in the volume of production from the level of the preceding year was larger tl' an that normally to be expected even in a growing country like the United States. Such is the record as presented in graphic form on Chart i and in tabular form in Table B. Moreover, both mineral and industrial production, as

THE purpose of the present study is to revise our index of the yield of io railroad bonds by correcting certain defects which have become apparent, so that it will more accurately register the fluctuations of pure long-time interest rates. Table X presents the maturity dates and other data for the bonds included in the old index.' The wide variation in maturity dates, ranging from I927 to 236i, and the fact that the bonds do not at present represent high class investments in railroad securities are obvious reasons for the construction of a new index.