The term 'Cost" refers to direct charges actually paid or payable (after discounts and in-. cluding freight) for (1) materials, parts, containers and supplies, (2) fuel, and (3) purchased electric energy, actually consumed during the entire year. Manufacturers were asked to include cost of materials for fuels consumed regardless of whether purchased by the individual establishment from other concerns, transferred to it from other establishments of the same company, or withdrawn from inventory during the year. Such cost items were to be included regardless of whether the materials were processed by the reporting establishment or by others for its account (contract work). For 1951, manufacturers were instructed to include in this item the cost of all materials sold in the same form as purchased. Such costs of "merchandising" items were deducted from the total cost of materials, supplies, etc. during the processing of the report forms. (See f below.)

Separate entries were required for each of items (1), (2), and (3) above, as well as for cost of work done for the reporting establishment on its own materials by other concerns (contract work). The sum of all of these items was deducted from value of shipments (excluding resales) in order to obtain value added by manufacture. It should be noted that the cost of fuel consumed (including anthracite and bituminous coal, natural and manufactured gas, fuel oil, liquefied petroleum gas, and other fuels) did not include fuel when used as a material in the manufacturing process--for example, coal in the production of coke. Such costs

were included with other materials cost under item (1) above.

b. Definition of "Inventories":

The values of beginning- and end-of-year inventories, respectively, were requested of all operating manufacturing establishments in the surveys, except those in the Printing and publishing industries group. As in the three most recent censuses, annual survey inventories data were collected under two major categories: (a) finished products and (b) materials, supplies, work in process, fuel and other inventories.

c. Definition of "Value of Products Shipped":

The amounts under the heading of "value of products shipped', whether shown as industry totals or as class of products totals, represent the received or receivable net selling values, f.o.b. plant, after discounts and allowances, and excluding freight charges and excise taxes. Manufacturers were asked to include in shipments all products made by or for each establishment from materials owned by it, whether sold or transferred to other establishments of the same company (i.e., other manufacturing plants, wholesale branches, central warehouses, etc.). For 1951 goods resold in the same condition as when purchased were reported in the shipments item. Such resales" were deducted from the total value of shipments during the processing of the report forms. (See f below.)

Products made by an establishment from materials owned by another establishment were included only in the shipments reported by the latter establishment, and the payments received by the former establishment for such work were reported by it in the shipments section of the form as "receipts for contract work.''

d. Shipments by classes of products:

As a

The number of product classes for which data are shown in 1951 has been increased considerably over that shown in the previous surveys. Since the 1951 form included a request for 1950 shipments as well, it has been possible to extend the product class data coverage for that year as well. In general, data have been withheld only for those product classes for which the standard error of estimate exceeds 15 percent, although a small number of estimates are withheld on the basis of reasonableness when compared with related data, or for considerations of national security. result, estimates are shown for well over half of the 1,000 product classes. It should be noted that the statistics for about 70 of the product classes were derived from the Bureau's "Facts for Industry'' surveys, or from commodity surveys of other Federal agencies in which the coverage was more complete than in the annual surveys. (Part II of this report presents a summary of the commodity data collected in the "Facts for Industry" series. A more detailed discussion of this series is given in the text preceding that part.)

An added feature of the product class table is the inclusion of "4-digit" group totals of product classes, where the degree of duplication among the product classes is not excessive. These sums represent the total value of shipments of product classes "wherever made" (i.e., regardless of the industry classification of the establishments reporting such product class values). Such totals, of course, are particularly useful where several individual product classes in a group have been withheld because of high sampling errors.

The total shown for these "4-digit' aggregates should not be confused with the total value of shipments for an industry. The latter includes all the shipments of establishments classified in the industry, including shipments of product classes secondary to the industry. The value shown for a product class (5-digit) represents total shipments of that class by all industries. Thus, the value shown for a "4-digit" aggregate of product classes represents total shipped by all industries.

e. Duplication in Cost of Materials and Value of Products Shipped Totals:

The aggregate of the cost of materials and value of shipments figures for industry groups and for all manufacturing industries combined includes large amounts of duplication, owing to the use of the products of some industries as materials by other indústries. With some important exceptions, such as ''Steel works and rolling mills'' and ''Motor vehicles and parts," this duplication is not significant within individual industries but arises from the addition of totals of related industries representing successive stages in the production of finished manufactured products. Examples are the addition of flour mills to bakeries in the Food and kindred products group, and the addition of blast furnaces to steel mills in the Primary metal industries group. Estimates of the over-all extent of this duplication indicate that the value of manufactured products, exclusive of such duplication-namely, the value of finished" manufactures-tends to approximate two-thirds of the total value of products reported in the annual surveys. Because of the unknown and varying amounts of duplication contained in cost of materials and value of products shipped, these figures are not shown for industry groups and States. They are also omitted for a small number of individual industries for which the proportion of duplication in value of shipments is believed to exceed 10 percent.

f. Value added by Manufacture:

"Value added by manufacture' measures the approximate value created in the process of manufacture. It, therefore, provides the most satisfactory census measure of the relative importance of given industries for the United States as a whole or for geographic areas. Value added is calculated by subtracting the cost of materials,

supplies, and containers, fuel, purchased electric energy, and contract work from the total value of shipments. (Both the cost and value of merchandise resales are excluded from this calculation.)

Value added by manufacture should not be confused with "income produced in manufacturing."" The latter figure is compiled by the Office of Business Economics, Department of Commerce. The main difference between these two measures arises from the fact that income produced excludes, in addition to cost of materials, such additional costs as depreciation, the labor costs involved in maintenance and repairs, State and local taxes (other than corporate income taxes), advertising, etc. These deductions in the Office of Business Economics income produced estimates are partly offset, however, by the inclusion of employer contributions to Social Security as a form of income and by the fact that the national income estimates are to a large extent prepared on a company rather than an establishment basis.

g. Products Bought and Resold Without Further Manufacture

The report forms for the annual surveys covering 1949 and 1950 included a separate inquiry (Item 9) for reporting the ''merchandising" activity of manufacturing plants i. e., goods resold in the same condition as when purchased. For 1951, however, the merchandising inquiry was integrated with the costs and shipments sections of the report form. The cost of products bought and resold without further process was incorporated with the cost of materials item. Receipts from the resales of such products were included with the shipments data. As has been indicated above, however, the merchandising data were subtracted out to arrive at cost and shipments values for the manufacturing activities of the plant only.

An analysis of the 1951 entries for sales and cost of products bought and resold without further manufacture indicates that receipts from merchandising resales by operating manufacturing plants amounted to roughly 2 to 3 percent of their receipts for manufacturing activities. Such information on merchandising transactions helped in determining whether establishments engaged in a combination of manufacturing and nonmanufacturing activities properly fall within the scope of the manufactures survey.

The areas in which a combination of manufacturing and nonmanufacturing operations were most frequently reported are as follows: petroleum bulk terminals and petroleum refining; lumber distribution and mill work; poultry dressing and fresh egg distribution; feed milling and distribution of hay, grain, etc.; ice manufacturing and fuel distribution; and meat processing and meat distribution.

10. Expenditures for New Plant and Equipment

In the annual surveys as in the 1947 Census, manufacturers were requested to report expenditures made during the specified year for permanent additions and major alterations that were charged to the fixed asset accounts of the individual establishments and were of the type for which depreciation accounts are ordinarily maintained. This inquiry was restricted to establishments that were in operation at any time during the report year and, therefore, did not include expenditures during that year for constructing and equipping new establishments, or renovating idle establishments. Information on capital expenditures of this type was obtained for the first time in the 1951 Annual Survey by means of a special report form, MA-101 (reproduced in Appendix E).

This form was distributed to (a) the "largest" companies (i. e., approximately 500 companies that were largest in terms of 1947 employment), (b) other companies in the Annual Survey which were known to have new manufacturing establishments under construction, and (c) a subsample of slightly less than 600 of the remaining companies in the Annual Survey sample.

Separate estimates of capital expenditures are presented in the tables for establishments in operation and for establishments under construction or renovation. Since data on the latter type of capital outlays were not collected in the past, only the estimates for the establishments in operation are directly comparable with figures published in prior manufactures censuses and annual surveys.

Although the introduction of Form MA-101 in the 1951 Annual Survey of Manufactures fills in a long-recognized gap in census statistics on manufacturing capital expenditures, the scope of census coverage still is not identical to that of the joint Office of Business Economics-Securities and Exchange Commission survey. The census data relate only to manufacturing establishments, whereas the OBE-SEC series cover all establishments, nonmanufacturing as well as manufacturing, operated by manufacturing companies, and exclude manufacturing establishments of companies engaged primarily in nonmanufacturing activities. Both series, it should be noted, exclude expenditures for plant and equipment at establishments owned by the Federal Government but operated under lease by private companies.

Authority as a part of the defense mobilization program - NPAF-1 and NPAF-103. Accordingly, it was possible to omit this section from the 1951 Annual Survey of Manufactures reporting form, and use the data obtained from the defense surveys, thereby reducing collection and processing costs.

The two quarterly defense surveys, NPAF-1 and NPAF-103, both called "Report of Plant Operations", included plants classified in the four broad industrial groups: Fabricated Metal Products, Machinery (except electrical), Electrical Machinery, and Transportation Equipment. In addition, plants classified in the iron and steel forgings industry (3391) were included. Reporting was required in these surveys for all plants classified in these selected metal consuming industries and which showed an average employment of 100 or more in the 1947 Census of Manufactures. Also included in these surveys was a sample of the smaller establishments in these industries.

Information on the defense surveys was collected quarterly during 1951 except that the survey of smaller plants (NPAF-103) was not conducted for the first quarter of 1951. It was therefore necessary to estimate first quarter metals consumed data for these plants in order to obtain yearly totals. These estimates amount to about 2 percent of the year's total consumption of the specified metals.

b. Comparability of data published for 1951, 1950, and 1949

For 1950 and 1949, plants in the metal fabricating industries were required to report their consumption of five types of metal mill shapes and castings: (1) iron castings, (2) carbon steel, (3) alloy steel, including stainless, (4) aluminum, and The consump(5) copper and copper-base alloys. tion of each of these metals was divided between metals purchased (or received from other establishments of the same company), for which both quantity and cost data were collected, and metals produced and consumed in the same establishment for which only quantity figures were obtained. For these years, the reported data covered consumption for all purposes, i.e., for production of fabricated products; for maintenance, repair, and operating purposes; and for consumption and alteration of plant facilities.

For 1951, however, the following differences in data collected in the defense surveys should be noted. (1) Establishments were not required to include data on consumption of iron castings in the NPAF-103 survey. The table for iron castings is, therefore, omitted for 1951. (2) No separation of consumption data was required between metals purchased (or received from other establishments of the same company), and metals produced and consumed in the same establishment. Such information is, therefore, not available for 1951. (3) The NPAF-1 survey excludes metals consumed data for those establishments which used metals in

amounts less than specified minimum quantities. The minimum quantities for reporting for each shape and form were: carbon steel, 30 tons; alloy steel, stainless steel, aluminum, and copper and copper-base alloys, 5 tons.

The metals consumed were defined to cover only those processed to the mill or foundry level, excluding metals fabricated or otherwise processed beyond this level. Machined castings were considered as processed beyond the foundry level. The consumption estimates shown in the tables thus represent only the direct use of the specified mill shapes and castings and not the total metal weight of the products of the given industry. For example, the steel consumption shown for the motor vehicles industry consists only of steel directly consumed in the form of rough castings, sheets, bars, wire, etc.; and does not include the weight of metal in subassemblies, stampings, forgings, wire products, etc., produced in other industries.

The definitions of mill shapes on the defense surveys for 1951 are similar to those for the previous years with a few exceptions. For 1951, aluminum foil and certain ferrous wire products such as nails, staples, etc., were treated as mill shapes and were reported by the consumers of these products. (See CMP Reg. 1, Schedule 1). In the 1949 and 1950 Annual Survey of Manufactures, and the 1947 Census, these materials were considered as fabricated products and metal consumption was obtained from the producers of such items.

Except for one change, the definitions followed in the 1949 and 1950 annual surveys were identical. This one change was in regard to the definition of insulated wire and cable and it should be noted that, in this respect, the 1951 defense survey definition was in agreement with that for 1950. In the 1949 survey (as in the 1947 Census) insulated wire and cable was considered to be a fabricated product, for which data were collected on the consumption of bare wire used in its manufacture; in the 1950 and 1951 surveys insulated wire and cable was treated as a mill shape for which consumers were required to report the copper content of such wire and cable.

Consumption of Forgings

Data were not collected for any of the surveys on the consumption of forgings, and in order to account for the quantity of steel thus omitted, the forgings industry (3391) was required to report its consumption of steel (ingot, billet, and bars) in the production of forgings. As this industry was not included in the NPAF-103 survey, these data were estimated on the basis of the NPAF-1 coverage compared with the 1947 value of shipments for the forgings industry.

d. Limitations of Data on Metals Consumed

In making comparisons with statistics on

be noted that the metals consumed data shown in the tables are limited to the major metal fabricating industries, which fall within the following broad industrial groupings: Fabricated Metal Products, Machinery (except electrical), Electrical Machinery, and Transportation Equipment. With the exception of the iron and steel forgings industry (3391), therefore, these tables exclude the consumption in those primary metals industries (major industry group 33) also engaged in fabricating metals products, as well as in such other significant metal consuming areas as Furniture and Fixtures (Major Group 25). Similarly, consumption in nonmanufacturing activities, such as construction, transportation, mining, agriculture, and public utilities, and shipments for export are not covered. For each metal shown, it is believed that the estimates of consumption in manufacturing represent over 70 percent of the total consumed in all uses.

12. Estimating Procedures Used in the Annual Surveys

Most of the annual survey estimates were derived by combining the 1947 Census (universe base) totals, which were not subject to any sampling error, with sample estimates of the amount of change from 1947. Estimated increases from 1947 were added to the corresponding 1947 Census universe totals, and estimated decreases were subtracted from the corresponding base totals in deriving the final estimates.

This difference estimating formula was used, with few exceptions, for all the general statistics estimates, for most of the product class estimates derived from the Annual Survey sample, and for most of the 1949-1950 metals consumed estimates. It was not used for any estimates based on reports from logging or sawmill establishments (industries 2411 and 2421). Less important exceptions included estimates in scattered cells of the size distribution table, and a few of the 1949-1950 metals consumed estimates. Neither was the difference formula used for the detailed statistics: expenditures for new plant and equipment, inventories, fuels consumed, and electric energy purchased. In all cases where this formula was not used, the estimates were developed by simply inflating the current figures for the sample establishments and summing the inflated figures. (A more detailed discussion is included in Appendix B.)

The standard errors of estimates derived by the difference formula tend to be appreciably smaller than the standard errors of estimates derived by the simpler formula (i.e., based on current data alone). The gain in efficiency realized is strongly affected by the correlation between base year and current year values for identical sample units. Relatively higher costs in relation to the expected benefits led to the choice of the simpler

Various approximate formulas were used to estimate the standard errors of the estimates, as described in Appendix B. Generally, these approximations tended to overstate the errors, Moreover, the published standard errors were rounded upward in all cases (i.e., to the next highest integer for standard errors under 10 percent; standard errors of 11 to 15 percent were shown as 15 percent; etc.).

13. Qualifications of the Published Data

All tables published in this report contain columns showing the sampling variation associated with the estimated totals. The effect of such sampling variation must be considered in studying the apparent increase of decrease in the estimated totals from year to year.

The standard errors of change from the 1947 Census totals are solely a function of the standard errors of the Annual Survey totals. The approximate standard errors of the amount of change from 1947, therefore, can be derived by multiplying the estimated totals by their indicated percentage standard errors. It should be noted that the results of these calculations are absolute amounts, such as number of employees, dollar values, etc., rather than percentages. The standard error of the estimated amount of change between any two Annual Survey estimates is more difficult to measure, but will rarely exceed the large error of change from 1947.1

In addition to such sampling errors, individual figures may be subject to biases arising from procedural errors or response errors which are not reflected in ths "standard errors' and which were not detected in the editing of the report forms or in the review of the detailed machine tabulations from which the published tables were prepared. Among such errors are those resulting from improper coverage and sample weighting of

'A more conservative upper bound on the standard error of the estimated change between two Annual Survey estimates can be obtained by multiplying each of the estimates by its percentage standard error, squaring each product, adding the squares, and extracting the square root of the sum of squares.

establishments (i.e., sample control errors), incorrect reporting of data by respondents, and clerical and machine tabulation errors at the Census Bureau. Estimates which were subject to large uncorrected errors of this type were generally suppressed, along with other suspect estimates, when the final publication totals were systematically reviewed both for reasonableness and for consistency with other Census series and related data. Other specific qualifications of the published data are usually indicated in the appropriate headnotes and footnotes to the tables.

14. Disclosure of Data for Individual Companies

The Bureau of the Census is prohibited by law from publishing any statistics that disclose information reported by individual companies. In the annual surveys, the same practices used in the 1947 Census were followed in analyzing the published data for disclosures. (See "General Explanations, " 1947 Census of Manufactures, Volume I, Section 15, or Volumes II or III, Section 14.)

15. Statistics for Selected Products

Part II of this volume contains an annual summary of available 1951 and 1950 quantity of production, and quantity and value of shipments data for approximately 2,300 products. The data for these products are comparable to the commodity statistics shown in table 6 of Volume II, Statistics by Industry, 1947 Census of Manufactures.

Related products have been grouped into product classes which are generally comparable to those used in the 1947 Census publications and are the same as those shown in Part I, Chap. III. -Value of shipments by selected classes of products.

The information in Part II was obtained in the current commodity statistics surveys of the Bureau of the Census and has been previously published in monthly, quarterly, or annual releases for related groups of products in the "Facts for Industry" series.

See the introduction to Part II for a further discussion of these commodity figures.