Chapter

XXI. Publication of BOP Statistics

Author(s):
International Monetary Fund
Published Date:
March 1995
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Introduction

1137. This chapter discusses publication of the output of the BOP statistical process. In some respects, publication is the most important part of that process.

1138. The term publication refers to the release of data to the public through various media. Such releases would include tables appearing in general and in specialist BOP publications; time series disseminated via computer disk, computer tape, modem, or CD-ROM; and specially released computer printout tables. Publication also encompasses other material that may accompany data released to the public. Such material could include explanatory notes, analytical comments, graphs, technical material, and articles of interest. In addition to BOP and IIP statistics, the compiler may wish to publish information showing the links between the BOP and other bodies of data or supplementary statistics.

Consultation with Users

1139. User requirements are paramount for determination of statistics to be disseminated. The compiler should attempt to ensure that published information will meet these requirements, which can be best ascertained from regular discussions with users. (See chapter 18, paragraph 840 for further information.) Although governmental economic policy agencies (such as the central bank, the ministry of finance, and the planning agency) are key users, the compiler should also consider the requirements of other parts of government, financial institutions (both national and international), industry, educational institutions, the press, and the general public. Ultimately, governmental economic agencies should confer and negotiate with the larger community of users, and an authoritative set of BOP statistics is essential for this purpose. The BOP compiler should be the recognized author of official BOP statistics.

1140. One of the main functions of BOP statistics is to provide valuable input for official policy formulation. Therefore, a range of BOP data is typically disseminated to relevant official institutions. In disseminating such data, the compiler should make every effort to ensure that all users have equal access to the information. Equal access assures users of the compiler’s impartiality and also imposes useful discipline upon the compiler. Users with different perspectives afford a broader critical appraisal of the statistics. Discovery of weaknesses, which may be very useful and occasionally painful, through external assessment of data should strengthen the compiler’s determination to provide statistics of high quality.

Periodicity

1141. Periodicity refers to the frequency of the reference period. BOP statistics are usually compiled on a monthly, quarterly, or annual basis; production of IIP statistics tends to be annual, although compilers in some countries prepare quarterly IIP statistics. The period chosen will depend on a number of factors, including user requirements, types of data collections available, and resources available to the compiler.

1142. For economies in which the external sector acts as a constraint on economic activity or is otherwise a focus of government economic policy, users will require frequent and up-to-date data. In particular, international lending institutions providing significant BOP financing to the official sector require frequent and current statistics.

1143. The periodicity of different data sources may vary. An ITRS usually provides data on a monthly basis because the system measures transactions on an essentially continuous basis. The nature of other sources often permits the compiler to choose the periodicity. On the one hand, it is desirable to collect data frequently and thereby obtain up-to-date information of good quality; on the other hand, less frequent collections require fewer processing resources and are often perceived as less burdensome for data providers.

1144. As a general rule, compilers should aim, at a minimum, to produce quarterly BOP statistics. Quarterly data should be adequate for the requirements of many users and for the purpose of compiling national account statistics. Annual (and less frequent) statistics are not sufficiently timely for most users, and the compilation of such statistics is often error prone. More frequent collection and compilation activity encourages better reporting of data, development of good methodologies, and timely feedback from users. In contrast, less frequent collection and compilation activity often suffers from low resource allocation, staff turnover between periods of data reporting and compilation, more reporting and compilation errors, and less feedback from users.

1145. A monthly periodicity for BOP statistics is seen as important in a number of countries, particularly those in the EU. In these countries, many of the data sources are available monthly, and the additional cost of producing monthly statistics is not considered to be a major factor. Some countries, while not having all the detailed data available to produce a complete monthly BOP statement, produce a less detailed or partial monthly BOP statement.

1146. A word of caution about monthly statistics is warranted. Monthly statistics may be volatile, preliminary, and subject to revision; therefore, such statistics should be interpreted with care. Users should be informed of the limitations as they may place undue importance on the latest monthly statistics. (For example, release of monthly BOP statistics in some countries may cause reactions, which reflect lack of understanding among users, in foreign currency and other markets.)

1147. This Guide suggests that those countries producing annual IIP statistics should strive to produce these statistics at quarterly intervals, if this is the periodicity of BOP statistics. As mentioned elsewhere in this Guide, co-production of BOP and IIP statistics helps to ensure the quality of both. If countries are not currently producing IIP statistics, production of annual statistics (at least) should commence as soon as possible.

Frequency and Timeliness of Publication

1148. Frequency of publication need not coincide with periodicity of BOP compilation. Nevertheless, there are many advantages, including timeliness, if publication frequency and compilation periodicity do coincide.

1149. Timely publication of statistics is essential if the compiler is to satisfy user requirements. The compiler should set, and adhere to, publication targets. Achievement of targets requires careful scheduling of tasks involved and development of techniques that produce timely statistics of good quality. Management of the statistical process for achievement of timely results is addressed in the previous chapter.

1150. Table 21.1 sets out some guidelines concerning times of publication. Compilers in some countries achieve targets that are better than the guidelines, while various constraints prevent others from reaching these targets.

Table 21.1Target Timetables for Release of BOP Statistics After the Close of Reference Periods
FrequencyLarge CountriesSmall to Medium Countries
MonthlySix weeksOne month
QuarterlyThree monthsTwo months
AnnuallySix months1Three months

1151. There are often trade-offs between level of detail and timeliness of publication. From a user’s viewpoint, there may be advantages if some compromises are struck. Users generally require very detailed and timely statistics. However, users may not require detailed statistics on a frequent basis. Therefore, some countries have developed strategies to maximize responsiveness to users. Preliminary BOP statistics are released in a press statement or a brief announcement that does not contain a lot of detail. These releases are followed up with publication of more details at a later date. Other countries make the maximum amount of detail available on an annual basis and less detail available at more frequent intervals.

1152. The compromise among timeliness, frequency, and level of detail may depend upon factors such as periodicity of underlying source data and resources and technology available to the compiler. Each compiler should consult with users to decide on the appropriate trade-offs (which will depend on national circumstances) among publication frequency, level of detail, and timeliness.

Dissemination Media

1153. The increased availability of computer technology has affected the way that BOP statistics are disseminated. Printed publications are still the most common form of dissemination, but that fact is changing. Although more BOP statistics are becoming available, fewer data are being released in printed form. Greater use is being made of computer tape, disk, CD-ROM, and on-line facilities to disseminate data.

1154. The format in which data are provided is also changing. BOP statistics in printed publications are usually presented in tables. These tables may show a number of related series over time (time series) or cross- classifications of data for a single period of time (cross-classified data). A logical way to consider data, at least from the compiler’s viewpoint, is often inherent in the design of the table. Of course, it is possible to convert cross-classified data to time series but, in a publication, this conversion may require many pages. For example, a compiler may present 20 BOP series cross-classified by 20 main partner countries and country groups. The resulting table would consist of a matrix of 400 cells, which may fit on one or two pages. If the compiler wanted to show each of these cells in the form of annual time series over 10 years, there would be 4,000 cells. Obviously, the number of pages required might not be practical.

1155. In contrast, data distributed in computer readable form are usually provided as time series rather than as tables. This approach has been adopted because compilers and users may have different software, and it is usually not a difficult task for recipients to devise tables into which the time series may be loaded. This approach also permits users to tailor their own data structures.

1156. With the advent of database technology, the conflict among detail, frequency, and timeliness has lessened somewhat.

Supporting Material in Publications

1157. Supporting materials should be included in information released to users by the compiler. These materials could include an explanation of the BOP conceptual framework and classifications, an explanation of data sources and methods used to compile items in the accounts, and an assessment of the quality of data sources and methods. In addition, any release of data should be accompanied by some analytical comment that draws user attention to the main features of the data, to any important relationships in the statistics, and to any phenomena that may affect the statistical series. The material released should also include technical notes describing publication policy and additional sources of information, such as a public BOP database, that could be accessed.

1158. As it may not be appropriate or feasible to provide all these supporting materials with each release of BOP statistics, some strategy for preparing and disseminating supporting information should be developed. An explanation of available supporting material and how the material can be obtained should be provided with each release of BOP data.

1159. In addition to publishing BOP statistics regularly, it is important for compilers to produce detailed papers or separate articles for publication. Topics could include the BOP conceptual framework and classifications, data sources and methods used to compile the BOP, and assessments of the quality of statistics. Better informed users are likely to interpret and apply BOP statistics more wisely. Misconceptions about the meaning and measurement of certain items are common among users and cause problems for policy formulation and evaluation. Awareness of possible weaknesses in statistics permits the analyst to judge the level of confidence that should be given to particular estimates. Preparation of a document on concepts, sources, methods, and quality requires the compiler to articulate the issues involved. In turn, articulation of these matters often leads to a better evaluation of methodologies and, hence, indirectly encourages greater efforts to improve the quality of statistics.

1160. Preparation of a detailed paper or articles for publication on the conceptual framework, data sources, methods, and data quality may not be an immediate possibility for compilers in many countries, although a number have now produced such papers. Nevertheless, major releases on BOP statistics could be accompanied by concise, basic statements on the conceptual framework, data sources, etc. Such statements would assist users in understanding some of the issues involved.

1161. Some analytical commentary should accompany all releases of BOP statistics. When providing analytical comments, the compiler should keep in mind that formulation and evaluation of economic policy are the prerogatives of some other government body. However, an overcautious attitude can also be counterproductive. The compiler’s scope of responsibility includes explaining what the numbers mean and drawing user attention to certain features of the statistics.

1162. Many of those who are exposed to published BOP statistics do not understand the conceptual framework of the BOP. Analytical commentary may, by describing developments in key aggregates, explain links within accounts. Important links between the BOP and other statistics presented in the BOP release may also be explained via comments on relationships between summary tables and more detailed tables. The commentary can and should highlight any unusual or unexpected phenomena reflected in the figures. For example, if imports have risen sharply in the most recent period, the BOP compiler might (on the basis of a commodity analysis) explain whether the increase occurred across-the-board or resulted from long anticipated delivery of major items of equipment. This type of comment is both factual and helpful. Compilers unaccustomed to making analytical comment may begin with brief statements and expand gradually to appropriate levels.

1163. Suitable graphs may be used to supplement analytical comment. With developments that have taken place in computer software, graphs are becoming easier to produce. Graphs should be simple, clearly and consistently labelled, illustrative of interesting points, and used sensibly.

1164. Material accompanying release of BOP statistics should explain how current data relates to other published data, where additional information may be found, the nature and timing of revisions to past data, and how the BOP database may be accessed (if a public database is available). It is highly desirable to provide telephone numbers of persons who may be contacted for explanations of the statistics or for further information. Telephone contact with users expands compiler awareness of user desires and problems and permits the compiler to be more responsive. In addition, telephone contact may enable the compiler to determine the most common queries and address them in future statistical releases or through special articles published from time to time. Telephone contact also contributes to good public relations and a good image; these are important for the compiler, who needs to collect data from many parts of the community.

1165. Special articles in BOP publications are another means of providing users with a better understanding of some aspects of the conceptual framework, data sources, methods, and quality issues. These articles may range from brief technical notes to more detailed papers and may be published on an ad hoc basis.

Presentation of Key Aggregates

Introduction

1166. When tables are included in the publication of BOP statistics, it is most effective to present a key or summary table first and to follow this with more detailed tables.

1167. While many people may have different views on what key aggregates are, most compilers and users would agree on the following propositions. BOP series should be presented so that the distinction between the current account and the capital and financial account is clear. Within the current account, clear distinctions should be made between goods, services, income, and transfers. For current account items, it is desirable to show BOP credits and debits separately. Within the financial account, major aggregates should be shown. (In the sample statistical presentations in appendix 3, the main aggregates in the financial account are direct investment, portfolio investment, other investment, and reserve assets. However, some users may prefer to give greater weight to a classification of financial transactions by domestic sector.) Within the financial account, it is desirable to show transactions in external assets separately from transactions in external liabilities. The net errors and omissions item should be shown outside the current and capital and financial accounts.

1168. Key BOP aggregates can be presented in neutral fashion or in a form that shows an overall balance. Presentation of an overall balance is discussed in paragraphs 1174-1176.

Two-column BOP Presentation

1169. In the two-column presentation of the BOP (see table 21.2), credit and debit entries for each BOP item are shown in separate columns. This presentation is the best way to illustrate the BOP conceptual framework.

Table 21.2Two-column Approach to Presentation of the Balance of Payments
Item NumberCreditDebit
Current account
Goods2100/3100200300
Services2200/32004030
Income2300/33002228
Current transfers2379/33791410
Total2993/3993276368
Capital account2994/39941220
Financial account
Direct Investment
Abroad45055
In the host country455550
Portfolio investment
Assets46023
Liabilities46524
Other investment
Assets470332
Liabilities475322
Reserve assets480010
Total499596
Net errors and omissions49984

1170. Key BOP aggregates are presented in table 21.2. The reader may note that credit and debit entries are recorded (gross recording) for current account items (goods, services, income, and transfers) and for the capital account. For financial account items, either a credit or a debit entry is shown (net credit or debit recording). While the two-column approach is a good way of presenting the conceptual framework, analysts have moved away from this presentation as data cannot be presented in a time series format and there is less flexibility for showing balances that analysts may wish to see. Therefore, the single-column approach is often preferred.

Single-column Approach

1171. Table 21.3 illustrates the single-column approach, which represents a rearrangement of the series in table 21.2.

Table 21.3Single-column Approach to Presentation of the Balance of Payments
Item numberValue
Current account
Goods
Credit2100200
Debit3100-300
Balance4100-100
Services
Credit220040
Debit3200-30
Balance420010
Income
Credit230022
Debit3300-28
Balance4300-6
Current transfers
Credit237914
Debit3379-10
Balance43794
Balance on current account4993-92
Capital account
Credit299412
Debit399420
Balance4994-8
Financial account
Direct Investment
Abroad4505-5
In the host country455550
Portfolio investment
Assets46023
Liabilities46524
Other investment
Assets470332
Liabilities475322
Reserve assets4800-10
Financial account balance499596
Net errors and omissions49984

1172. In table 21.3, the analytical usefulness of the table is expanded by addition of a number of balances. Presentation of the table in a single- column format requires introduction of a sign convention. In table 21.3, the absence of a sign (a positive entry) represents a credit, and a minus sign represents a debit. In some presentations, for current account debit items and gross financial account credit entries (such as loan repayments), no sign is shown because the sign is clearly understood. The policy on the use of signs in published material should be clearly stated.

1173. The single-column approach facilitates presentation of data for many periods (time series) in a single table, and each subsequent period can be added to the right of the table.

Presentation of an Overall Balance

1174. Table 21.3 does not show an overall balance. The concept of an overall balance is discussed in note 20 on page 161 of the BPM. There is no accepted international standard as to what constitutes an overall balance of payments outcome, and different definitions are used in different circumstances. In general, certain items or transactions are excluded from “above-the-line” entries to arrive at a measure of the overall balance.193 In fact, as the BPM points out, the analyst has a number of such balances to choose from.

1175. For example, as a measure of the overall balance, an analyst may wish to exclude reserve assets, exceptional financing transactions, and LCFAR from “above-the-line” transactions. Exceptional financing includes debt cancellation (included in capital transfers), borrowing for BOP support (included in portfolio or other investment), debt-to-equity swaps (included in direct or portfolio investment), rescheduling of debt (included in portfolio or other investment), or incurrence of arrears (included in other investment).

1176. Table 21.4, which appears on page 234 and represents a rearrangement of table 21.3, shows the impact of creating an overall balance. For the purpose of calculating an overall balance, reserve transactions and the following exceptional financing transactions are excluded from “above-the-line” items: debt forgiveness of 7; debt to direct investment equity swap of 17; cancellation and re-issue of securities of 9; loan rescheduling of 11; and incurrence of arrears on interest payments of 3. In addition, securities (of 3) issued by resident banks are acquired by foreign central banks as part of their reserves (LCFAR).

Table 21.4Presentation of Balance of Payments Showing an Overall Balance
Item number1Value
Current account
Goods
Credit2100200
Debit3100–300
Balance4100–100
Services
Credit220040
Debit3200–30
Balance420010
Income
Credit230022
Debit3300–28
Balance4300–6
Current transfers
Credit237914
Debit3379–10
Balance43794
Balance on current account4993–92
Capital account n.i.e.
Credit2994*5
Debit399420
Balance4994–15
Financial account n.i.e.
Direct Investment n.i.e.
Abroad4505–5
In the host country n.i.e.4555*33
Portfolio investment n.i.e.
Assets46023
Liabilities n.i.e.4652*–8
Other investment n.i.e.
Assets470332
Liabilities n.i.e.4753*8
Financial account n.i.e. balance4995*63
Net errors and omissions49984
Overall balance–40
Financing of overall balance
Reserve assets4800–10
Exceptional financing490047
LCFAR49203

Presenting the Summary Table

1177. Appendix 3 provides a model BOP summary table (table P1), which the compiler may consider for inclusion in published material. The model table does not present an overall balance, but it does present, as memorandum items, elements that the analyst may use to construct an overall balance. The advantage of not presenting an overall balance is that the relationship between the summary table and those that follow is clear. However, this Guide makes no recommendation as to whether or not the compiler should use a presentation that includes an overall balance; this decision is left to individual compilers, who should consult with BOP users. The summary table also includes some key exchange rate series as memorandum items.

Presentation of Detailed and Supplementary Statistics

Introduction

1178. Model tables P2 through P10 in appendix 3 are core tables that the compiler may wish to consider for use in publishing BOP material. These tables show how the compiler may present BOP statistics, including statistics on the IIP and external debt. The tables are not mandatory; BOP compilers will have their own priorities in this area. Some of the items shown in the tables may not be relevant in some countries, while other items omitted from the tables may be very important. The tables include primary standard components presented in the BPM and make a good starting point for deciding which tables should be used in the publication of BOP statistics. Compilers could regard the tables as a target to be published on a quarterly basis. There is much more BOP and related information that the compiler may consider essential to the work of analysts and wish to publish. Possible extensions to core tables are described in table 21.5. This additional information could be published quarterly or annually, made available on a public database, or released on request.

Table 21.5Additional Statistics
1. Goods
A more detailed commodity breakdown and a further disaggregation of BOP adjustments than that shown in table P2 could be published. Many countries also publish some quantity data in addition to values for certain important export or import commodities. Some countries publish commodity detail in constant prices and corresponding price indexes or implicit price deflators. These data may be published in seasonally adjusted as well as original terms. Some countries publish goods classified by broad economic category.
2. Services
More detailed breakdowns than those shown in table P3 could be provided. For transportation, the breakdown could include, as recommended by the BPM, the type of service (passenger, freight, and other) and mode of transport (sea, air, and other).
For travel, business and personal travel could be separately distinguished, as is recommended by the BPM. In addition, if the compiler has developed a data model for estimating travel from component series (for example, numbers of travelers by classes of travel multiplied by expenditure per head), the component series could be published.
Breakdowns for other business services and personal, cultural, and recreational services could, as recommended by the BPM (see Table 10.1), be provided.
Some countries publish a breakdown of services in constant prices and corresponding implicit price deflators. These data may be published in seasonally adjusted as well as original terms.
3. Income
Compensation of employees is shown as a single item in table P4; this treatment is consistent with recommendations of the BPM. This item could be further subclassified to show wages and salaries and actual and imputed social contributions of the employer. In addition, if the compiler has developed a data model for estimating compensation of employees, details of the component series (for example, the number of nonresident workers and the per capita income in the host economy) could be provided.
For investment income, more detailed breakdowns than those shown in table P4 could be provided. Such breakdowns could, as recommended by the BPM (see Table 13.1), include complete subclassification by institutional sector. In addition, detailed income yield analysis and seasonally adjusted series could also be provided.
4. Transfers (current and capital)
Information additional to that provided in tables P5 and P6 could be published, especially in respect of components of transfers not reflected in the standard components. These could include development assistance (such as budgetary assistance, project aid, other forms of financial assistance, technical assistance, education, and training), military grants, various taxes, and pension components. In respect of development assistance provided, a reconciliation showing the relationship between official aid statistics and aid transfers shown in the BOP would be useful.
5. Financial account and IIP
More detailed breakdowns than those shown in tables P7 to P8 could be provided. These breakdowns could include the complete classification recommended by the BPM (see tables 10.3 and 10.4) and a breakdown of exceptional financing and LCFAR items. Detailed breakdowns of non-flow changes in stocks (such as exchange rate changes, price changes, and other reconciliation items) could also be provided in the form of a reconciliation table. Information on the currency composition and residual maturity of debt are also often analytically useful.
6. Linkage series
Tables could be included to illustrate the relationship between the BOP and other statistics, such as national accounts, money and banking, and government finance statistics. Statistics on exchange rates could also be presented.
7. Partner country statistics
Cross-classification of BOP and IIP items by partner country is important. The level of detail should be at least that shown in table P1 although, for reasons of sensitivity, reserves may be combined with other investment.

Goods

1179. Table P2 in appendix 3 provides for a commodity classification of exports and imports of goods. Such a classification, while not part of the standard components of the BPM, contributes greatly to analyst understanding of developments in transactions in goods. It is also highly desirable that the relationship between recorded trade statistics (which may come from ITS or even an ITRS) be demonstrated and that BOP adjustments be explicitly shown, although the adjustments need not be shown in detail. Showing the adjustments reveals differences between ITS (or an ITRS) and BOP items for goods; it also helps the analyst to ensure that, if using ITS data, he or she has the same generation of data as the BOP compiler. In table P2, it is assumed that BOP adjustments are made at the commodity level. If this is not possible, BOP adjustments should still be included explicitly in the table and not merely shown as memorandum items.

Services, Income, and Current Transfers

1180. Breakdowns for services, income, and current transfers (included in tables P3, P4, and P5, respectively) do not include all subclassifications recommended by the BPM. However, these tables show the minimum list of categories that should be published.

Capital Account

1181. Table P6 is a model capital account table. Classifications shown are consistent with the standard components of the BPM.

Financial Account and IIP

1182. The breakdown of the financial account and the IIP statement shown in tables P7 and P8 does not include all subclassifications recommended by the BPM—partly because additional detail on the domestic sector is included in table P9. The reconciliation between stocks and transactions is not shown in any of the model tables, although reconciliation items may be derived by deducting financial flows recorded in table P7 from the change in stocks recorded in table P8. For this reason, it is important that classifications in both tables be presented on a consistent basis. As countries become more sophisticated in the compilation of IIP statistics, it is suggested that a full reconciliation table (similar to Table 10.4 in chapter 10 of this Guide) be published.

External Debt Statistics

1183. Table P9 is included for two reasons. First, table P9 provides a classification, which is not included in tables P7 and P8, of stocks and financial transactions by domestic sector. Second, table P9 underlines the link between debt instruments in the BOP and the IIP and external debt statistics.

BOP Ratios

1184. The compiler may wish to calculate a number of BOP ratios for verification and publication purposes. Table 21.6 sets out a series of such ratios, which include both flow and stock series. When flow series are used in the calculation of a ratio, they should be annualized. That is, data for the latest 12 months or latest four quarters (not just the observation for the most recent period) should be included in the formulae. Stock position data used in the calculation of ratios should consist of stock positions at the ends of reference periods for which ratios are being calculated.

Table 21.6Selected Balance of Payments Ratios
Description
Exports f.o.b./current account credits
Imports f.o.b./current account debits
Goods and services credits/gross domestic product
Goods and services debits/gross national expenditure1
Investment income credits/current account credits
Investment income debits/current account debits
Balance on goods and services/gross domestic product
Current account balance/gross domestic product
Reserves at end of period/imports of goods and services
Gross external debt/gross domestic product
Gross external debt/exports of goods and services
Net external debt/gross domestic product
Net external debt/exports of goods and services
Net international investment position/gross domestic product
Debt service/exports of goods and services

1185. Each ratio is fairly self explanatory, except for the debt service ratio. Debt service should, theoretically, be calculated as interest payable plus repayments on long-term debt liabilities and any net reductions in short-term debt liabilities.194 Calculation of the latter two items requires series not included in the list of standard components recommended in the BPM. These additional series are repayments on long-term debt liabilities that form part of direct investment in the host country; the net reduction of short-term debt liabilities that form part of direct investment in the host country; redemptions of bonds and notes; and the reduction, resulting from secondary market transactions, in bonds and notes held by nonresidents. To avoid compiling these additional series, the compiler could take a simpler approach. Repayments on debt could be calculated as the sum of the reduction in the debt component of direct investment in the host country, reductions in non-equity portfolio liabilities, repayments of Fund loans and credit, repayments of other long-term debt liabilities recorded in other investment, and reductions in short-term debt liabilities recorded in other investment.

1186. As another alternative, compilers in some countries calculate debt service ratios simply as interest debits as a percentage of exports of goods and services. However, this approach would generally be warranted only for countries not facing constraints on the availability of external financing.

Seasonally Adjusted, Trend, and Constant Price Series

1187. Movements in statistical series may be affected by three influences: seasonality, trend, and an irregular component. In addition to publishing BOP series at original values, some countries publish seasonally adjusted series for certain items. Seasonal adjustment is a process designed to take account of the variation, which is due to normal seasonal influences, in a time series from period to period. Normal seasonal influences are those that tend to occur regularly once or more a year. By definition, annual series cannot be seasonally adjusted. Therefore, publication of seasonally adjusted statistics will be restricted to those with monthly or quarterly periodicity, although not all such series will be subject to discernable seasonal influences.

1188. Mathematical techniques are available to remove seasonal influences from time series. Many analysts find seasonally adjusted statistics extremely useful, particularly those relating to goods, services, and income. Accordingly, compilers should investigate the possibility of seasonally adjusting BOP statistics if such adjustments are not already being made.

1189. Seasonal adjustment removes the effect of one movement influencing statistics. Many users of BOP statistics are, however, interested in the trend element. To accommodate these users, some countries prepare trend estimates derived by “smoothing” seasonally adjusted series. There are a number of trending techniques that could be used, and compilers should at least investigate these.

1190. One difficulty in analyzing certain BOP statistical series, particularly those relating to goods and services, is that movements over time reflect changes in both quantities and prices. In many cases, economic analysis is best served by analysis of changes in quantities (or volumes) only. Therefore, some countries publish constant price estimates.195 Constant price estimates are series expressed in base period prices to explain changes in quantities in monetary terms. Constant price estimates are only meaningful when analyzed in the form of a time series.

1191. Constant price estimates can be derived by two methods. In one method, current period quantities for each component are multiplied by base period prices, and results can be aggregated across components. In the second method, current price estimates are divided by an appropriate price index having the same base period as the constant price estimates being derived. The first method is conceptually pure; however, the second method is often more practical.

Historical Data

1192. Often, historical data are not well managed. As classification schemes change, there may be problems with relating data that have been collected via different classification schemes. Poor documentation or lack of resources may make it difficult to align historical data with current classification schemes. To the extent possible, historical data should be aligned with the current classification. This task may be onerous, but the benefits to current users and economic historians justify the effort.

Housekeeping Matters

1193. While not involving any major conceptual or methodological issues, housekeeping matters, such as preserving the security of BOP statistics until release time and ensuring simultaneous distribution to users, may consume the compiler’s time. This Guide strongly recommends that these matters be approached with the same intellectual vigor as other issues concerning the BOP.

1194. One issue that often arises is whether or not attempts should be made to recover the costs of publishing BOP statistics and related information. Generally, recovery of costs through fees charged for published material has much to recommend it. However, the main function of the compiler is to compile and make available to users (in the broadest sense of that term) statistics of good quality, and cost recovery should always remain a secondary consideration.

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