Table A-1. SEASONAL INDEXES USED TO ADJUST PRIVATE HOUSING STARTS: MONTHLY 1977 TO 1978 The implicit seasonal index is the ratio of the unadjusted number of housing units started in the United States to the seasonally adjusted national totals of housing units started. Table A-2. SEASONAL INDEXES TO ADJUST HOUSING UNITS AUTHORIZED IN PERMIT-ISSUING PLACES AND MANUFACTURERS' SHIPMENTS OF MOBILE HOMES: MONTHLY 1977 TO 1978 The implicit seasonal index is the ratio of the unadjusted number of housing units authorized by building permits in the United States to the seasonally adjusted national totals of housing units authorized. The implicit index does not include mobile home shipments. 2Based on data for the period January 1959 through September 1977. Table A-3. AVERAGE PERCENTAGE CHANGES AND RELATED MEASURES FOR MONTHLY HOUSING STARTS, PERMIT AUTHORIZATIONS, AND MOBILE HOME SHIPMENTS The following are brief definitions of the measures shown in this table. More complete explanations appear in Electronic Computers and Business Indicators by Julius Shiskin, issued as Occasional Paper 57 by the National Bureau of Economic Research, 1957 (reprinted from the Journal of Business, October 1957). 'ō' is the average month-to-month percentage change, without regard to sign, in the original series. 'CI' is the average month-to-month percentage change, without regard to sign, in the seasonally adjusted series. 'I' is the average month-to-month percentage change, without regard to sign, for the irregular component, which is obtained by dividing the cyclical component into the seasonally adjusted series. 'C' is the average month-to-month percentage change, without regard to sign, in the cyclical component. 'C' is a smooth, flexible moving average of the seasonally adjusted series. 'I/C' is the average month-to-month percentage change, without regard to sign, of the irregular component divided by the average month-tomonth percentage change, without regard to sign, of the cyclical component. It serves as an indication of the series' relative smoothness (small values) or irregularity (large values). MCD (months for cyclical dominance) gives an estimate of the appropriate time span over which to observe cyclical movement in a monthly series. In deriving MCD the average (without regard to sign) percentage changes in the irregular and in the cyclical component are computed for 1-month spans (Jan.-Feb., Feb. -Mar., etc.), 2-month spans (Jan.-Mar., Feb.-Apr., etc.) up to 5-month spans. MCD is the shortest span for which the average change (without regard to sign) in the cyclical component is larger than the average change (without regard to sign) in the irregular component; thus it indicates the point at which fluctuations begin to be more attributable to cyclical than to irregular movements. Since changes are not computed for spans greater than 5 months, all series with an MCD greater than "5" are shown as "6". MCD is small for smooth series and large for erratic series. Superintendent of Documents U.S. Government Printing Office Official Business FIRST-CLASS MAIL POSTAGE & FEES PAID CENSUS PERMIT No. G-58 The Construction CONSTRUCTION STATISTICS DATA FINDER Statistics Data Finder is a 12-page publication which lists all types of statistics published in the Construction Reports Series and in the quinquennial Census of Construction. Each series is described in the Data Finder as to geographic detail provided, frequency of publication, and period for which the data are available. Single copies are available upon request by writing to: Questions regarding these data may be directed to William K. Mittendorf, Chief, Construction Starts Branch, Telephone 301-763-5731. For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402. Postage stamps not acceptable; currency submitted at sender's risk. Remittances from foreign countries must be by international money order or by draft on a U.S. bank. Annual subscription price - domestic $14.00: annual subscription price - foreign $17.50. Single copy - domestic $1.20: single copy foreign $1.50. New privately owned housing construction was authorized in November 1978 at an estimated seasonally adjusted annual rate of 1,691,000 units in the 14,000 permit-issuing places. This is 2 percent below the revised rate of 1,719,000 for October 1978 and 7 percent below the rate of 1,822,000 for November 1977. New single-family units were authorized in of November at a seasonally adjusted annual rate 1,114,000 units compared with the revised October rate of 1,127,000. Units in apartment buildings with five units were authorized in or more November at an annual rate of 428,000 compared with the revised October estimate of 459,000. The November annual rate of permit authorized units in buildings with two to four units was 149,000 During the first eleven months of this year, 1,551,000 units were authorized by permits com pared with 1,571,700 units for the same period in 1977. interpreting changes in housing starts and building permits, note that month-to-month changes in seasonally adjusted statistics often show movements which may be irregular. It may take three months to establish an underlying trend for total starts and two months for total building permit authorizations. The statistics in this report are estimated from sample surveys and to subject sampling variability as well as errors of response and nonreporting. Estimated relative standard errors for preliminary data are shown in tables 1, 2, 4, and 5. An explanation of the reliability of the data appears in the appendix to Construction Reports, C20-78-10. Housing starts and building permits data do not include mobile home units. Mobile home statistics are shown in table 6. |