This chapter details how the estimates of natural resources that have been discussed in previous chapters can be recorded in a full sequence of economic accounts. It also covers specific compilation issues such as volume measures, time series, and quarterly estimates of depletion.
Measuring Natural Resources in the National Accounts
A Compilation Guide
Abstract
618. The main purpose of this chapter is to detail how the estimates of natural resources that have been discussed in previous chapters can be recorded in a full sequence of economic accounts.1
619. A key distinction in national accounts is between recording estimates in current prices and in constant prices (volume terms). In future, under the 2025 SNA, it is expected that growth estimates published by national statistical offices will include Net Domestic Product (NDP) growth as well as Gross Domestic Product (GDP) growth, and NDP will include depletion of natural resources as well as consumption of fixed capital (depreciation). As figures of economic growth are usually presented in volume terms, it is important to discuss how to obtain estimates of depletion in volume terms. Furthermore, the headline economic growth figures that are followed closely by policy makers and economic analysts are the quarterly growth estimates, so the estimation of depletion on a quarterly basis is also an important topic.
620. The outline of this chapter is as follows. The chapter starts in Section 6.2 with discussing the compilation of stocks and flows of natural resources in volume terms. Section 6.3 looks at the compilation of a time series of natural resources especially how to backcast asset values. This is followed by a discussion in Section 6.4 of quarterly estimates of depletion required to compile NDP at a quarterly basis. Section 6.5 presents split-asset calculations (how to calculate the government’s share of natural resource assets). Finally, Section 6.6 discusses full sequences of accounts (T-accounts) for the four types of resources discussed in Chapters 4 and 5 – subsoil assets, renewable energy resources, timber resources and forest land, fish resources – with the 2008 SNA and 2025 SNA recordings to illustrate the differences. A text box with a summary of key recommendations concludes the chapter.
621. Capital has a dual nature in economics: assets are a store of wealth and may also be used in production, contributing to economic growth. These different perspectives translate into different ways of removing the effect of changes in prices (as also expressed in SEEA Energy).2
622. When considering assets as a store of wealth, making comparisons over time is best served by deflating current asset values by a common price deflator such as a GDP deflator or the Consumer Price Index (CPI). For instance, if oil prices go up, the current value of subsoil assets will increase. An oil rich country will become relatively richer as the same amount of oil allows them to purchase more products. This increase in wealth is best expressed by deflating with the general change in the level of prices, which captures changes in a wide range of products and services purchased by consumers.
623. The other perspective that can be taken is the production perspective. The main intuition here is that sustaining welfare requires sustaining production possibilities (economic growth). In this perspective, it does not matter whether oil prices increase relative to prices of other products, as we would still be able to produce the same amount of products. Therefore, a comparison over time of the value of natural resources is best served by removing the effect of the price change of the resource, so we are left with the changes in the volume of the resource (e.g. the physical amount of subsoil assets).
624. The 2025 SNA (Chapter 18) contains a detailed discussion of measuring prices and volumes, although it does not specifically discuss balance sheets. Volume in national accounts includes not only changes in quantity, but also changes in quality of products or resources. The 2025 SNA generally prefers measurement in volume terms using a suitable (specific) price or volume index. For longer time series, the SNA recommends the use of chain indices. The SNA also prefers to speak about estimates in volume terms (or chain volume index) rather than estimates in constant prices, as the latter assumes the use of prices of a single base year.
625. Few countries have experience compiling natural resource estimates in constant prices or volume terms. However, the World Bank’s Changing Wealth of Nations (CWON) programme has included such estimates since the beginning. In the past, a general price deflator has been used; but the 2024 release of the CWON (World Bank, 2024[1]) applies a volume index (specifically a Törnqvist index) to distinguish physical changes from price effects.
6.2.1. Calculating monetary asset accounts in volume terms
626. As part of the work for this compilation guide, a worksheet showing how to calculate the monetary asset accounts including depletion in volume terms (constant prices) has been developed for the accompanying workbooks for subsoil assets, renewable energy, and timber resources and forest land.3 For fish resources, an alternative (Tier 1) method is proposed that allows calculating depletion in volume terms (Section 6.2.2).
627. After exploring three possible methods to remove the effect of price changes on the monetary asset accounts, the following approach is recommended:
When calculating the 2024 opening stock value (i.e. the 2023 closing stock value), we apply the evolution of the physical measure of the stock between 2023 and 2024. This is a common way to measure volume by using a base year price, in this case a constant in situ price (as in 2023), equivalent to a Laspeyres volume index. To see this, if we assume that there are no changes in the price of the resource, by definition the revaluation element is zero and changes in value are solely due to changes in physical units.
This is illustrated in the workbooks. For example, for subsoil assets in the worksheet “Volume terms estimates”, the recommended method:
Calculates the opening stock for 2024 (i.e. the 2023 closing stock value) in cell D10 by multiplying the opening stock for 2023 by the ratio of physical assets at the start of 2024 to physical assets at the start of 2023.
Calculates the flows during 2023 by multiplying the 2023 physical asset account flows (Stage 3_Year 2 worksheet rows 28-35) by the in situ price of opening stocks. The in situ price is calculated as: NPV of asset in current prices divided by physical stocks.
628. The results for the case of subsoil assets are shown in Table 6‑1. They include a figure of 20.9 for depletion in constant prices.
Source: Workbook: subsoil assets, Volume terms estimates worksheet.
629. This recommendation is based on the SEEA CF (§A5.40)
With the price, quantity and value of the natural resource in situ in hand, it is fairly straightforward to compute a volume measure of the stock of natural resources. In the case of a single homogeneous asset, the volume measure simply equals the evolution of the physical quantity in the ground. In the case of different types of natural resources, an aggregation procedure must be identified to construct a volume index across different types of natural assets.
630. In fact, Schreyer and Obst (2015[2]) propose a natural resource index that can be applied when aggregating across multiple natural resources. The index proposed by Schreyer and Obst (2015, p. 12[2]) is described as an example of a Marshall-Edgeworth type volume index:
Equation 6.1
with the average price of resource in situ; the stock of resource i at time t.
In case of a single resource, this index reduces to the development in physical stocks of the resource.
631. It should be noted that two alternative options for calculating the monetary asset account in constant prices were explored as part of the work on this compilation guide:
Alternative option 1: when calculating the 2024 opening stock value (i.e. the 2023 closing stock value), we apply the smoothed unit resource rent as in mid-2023 (i.e. of the previous year); this procedure can be applied in subsequent years leading to chained volume measures (by multiplication).
Alternative option 2: when calculating the 2024 opening stock value (i.e. the 2023 closing stock value), we express the smoothed unit resource rent of mid-2024 in 2023 prices.
632. These alternative options were not chosen for the default approach because the costing of depletion is aligned with taking a production perspective, where depletion costs are deducted to signal a future decline in income. But they are also shown (for reference) in the Volume terms estimates worksheets of the subsoil workbook.
6.2.2. Calculating depletion in volume terms using a Tier 1 method
633. If no physical asset account is available (for example for fish resources), compilers should apply a variation of the recommended approach where depletion is calculated both for opening and closing stocks by dividing these values (now in constant prices) by their respective asset lives at the beginning and end of the accounting period, followed by averaging.
634. This Tier 1 method is illustrated in the workbook for fish resources. First the asset value of the closing stock is expressed in constant prices by applying Alternative option 1.4 The depletion cost in volume terms is deducted from the opening stocks, with the remaining balance recorded as revaluation.
635. It is one thing to start compiling asset values of natural resources, but it is another to also construct a historical time series going back several years. When backcasting, it is useful to distinguish clearly between the principle being applied and the data sources being used.
636. Balance sheets are in principle always forward-looking (commonly referred to as ex ante) meaning that when compiling an estimate say for opening stocks of 2024, only information available at or around that time (recognising that compilation usually occurs several months later) is to be used. When compiling a historical time series, the same ex ante principle should be applied also for earlier years (say the period 2010 – 2024) to ensure a consistent time series and thereby facilitate correct interpretation by users. This means that even though we may have information available in retrospect (commonly referred to as ex post), for instance that a large discovery of subsoil assets was made in 2020, we should not use this type of information that was not known at the earlier point in time when compiling a historical series.
637. The difference between ex ante and ex post estimates can be very significant for natural resources. This is well illustrated by the example from de Haan and Haynes (2019[3]) reproduced in Figure 6-1. For resources such as natural gas, the ex ante estimates (solid blue line) are much more volatile than the ex post estimates (striped grey line) as they reflect discoveries, reclassifications, etc., when they occur.
Source: De Haan and Haynes (2019, p. 9 [Figure 1][3]).
638. Therefore, to compile a historical time series, it is recommended to first construct a time series of physical asset accounts for the resource, following the same ex ante principle. This should contain – to follow the subsoil assets example – information about discoveries, reclassifications, etc., when they occurred. As a second step, the asset value at each point in time should be estimated based on the physical data that was known at that point in time (without knowledge, say, of discoveries that occurred at a later date). Unit resource rents should be estimated by applying the same principles that are used when forecasting i.e. using the observed resource rents (say of the past three years) and assuming that extraction5 remains constant. This would guarantee that the resulting time series is compiled consistently.
639. Time series of national accounts data that are used for estimating resource rents (i.e. monetary data) are regularly updated, for instance during benchmark revisions. When estimating resource rents, it is recommended to always use the most up-to-date national accounts data for the whole time series (including previous years), however the physical asset accounts should not be revised (unless in case of errors). This does not violate the ex ante principle, as resource rents (as well as physical asset accounts) measure what actually occurred during each year. In other words, there is no problem using better ex post data sources for compiling a historical time series based on the ex ante principle.
640. With the increased focus that is expected under the 2025 SNA on net figures such as NDP, as discussed in Section 6.1, it is important to measure the cost of depletion quarterly (and ideally also compile quarterly balance sheets).
641. Ideally, quarterly estimates of depletion should be compiled in the same way as annual estimates. Regarding the top-down approach, which is recommended for the valuation of subsoil assets as well as several biological resources, there is a lot of quarterly data from the national accounts that can be used in the same manner as for annual estimates. However, when it comes to measuring depletion, the main challenges are that physical asset accounts are not available at that frequency and physical extraction/production figures are likely also to be unavailable or available only with a time lag. In addition, we may also have insufficient information for a resource rent calculation (revenues will be available, but not (detailed) costs). Therefore, deriving depletion from quarterly balance sheets is considered an advanced (Tier 3) method.
642. Compiling estimates for fixed capital stocks and their depreciation faces similar challenges. As explained by the OECD Measuring Capital handbook (OECD, 2009[4])
With the rising importance of quarterly information it would, in principle, be desirable to have a complete set of measures of stocks and flows of capital at quarterly frequency. Given quarterly measures, the annual figures could be consistently built up from the sub-annual data. This is, however, a highly unrealistic scenario. Most of the data sources required to build measures of capital stocks and flows are available at annual frequency or less and the relation between annual and sub-annual measures is not one of consistent construction of yearly data from quarterly observations. Most countries do not construct quarterly capital stock measures or balance sheets. Where quarterly flow variables are required such as for the estimation of consumption of fixed capital, they would typically be based on interpolations of annual data. (§15.6)
643. Although some countries, such as the United States apply a quarterly perpetual inventory model (PIM),6 most countries still apply some form of interpolation to produce quarterly estimates, using varying methods.7
644. For the estimation of depletion, it is recommended in the standard approach to apply, to the extent possible, a similar interpolation (or quarterly temporal disaggregation) method as used for estimating depreciation. This has also the advantage that it ensures consistency between depreciation and depletion estimates. Another possibility would be to apply the average ratio of depletion to output of previous periods (preferably using the same number of years as used for smoothing).
645. In the 2025 SNA, assets must be split between extractors (producers, usually in non-financial corporations) and the legal owner (usually general government) based on how much of the resource rent is captured by each party (see Chapter 3).
646. To calculate this, each workbook contains a separate worksheet entitled Split-asset calculations which calculates the legal owner’s share of resource rent (see Table 6‑2). In case the government is not the legal owner, as explained in Section 3.6, the calculation of resource rent should not be corrected for specific taxes less subsidies, but the split asset calculation remains similar. The resource rent is sourced from the worksheet that contains the resource rent calculation required for Step 1 of Compilation Stage 3 (within the workbook). Assuming that Stage 3 Step 1 has already been compiled, this process is automatic.
647. However, there is one additional item to be provided: rent payments to the legal owner (in the example general government) for a number of years (D45) (green cells).
648. The legal owner’s share is obtained simply by dividing the rent by the total resource rent. This is averaged over the last three years (consistent with the approach for smoothing resource rents in Step 4 of Compilation Stage 3). In the example for subsoil assets, 88% of the resource rent is captured by the legal owner. This proportion is used to split the natural resource asset (stocks) as well as the flows in the sequence of accounts such as depletion, revaluation and other changes in volume.
649. In case of composite assets (e.g. timber resources and forest land), it is important to distinguish between two possible cases of contracts between the legal owner and the extractor. The first possibility consists of a pure sale of inventories: in this case, payables from the extractor are the counterpart of the sale of inventories; no leasing of the underlying asset takes place and hence no rent payment. The second possibility is leasing of natural resources: in this case payables from the extractors are rent and hence no sale of inventories is recorded.
650. One could argue that in case a resource lease is established (e.g. for forest land), the extractor would start by harvesting from work-in-progress. However, it would be reasonable to assume that at the end of the lease (assuming sustainable use) the forest land would need to be returned in the same condition. This guide recommends (and this is also implemented in the timber example) that by default the work-in progress remains with the legal owner when splitting assets. In practical terms, the guide recommends that if the management of the forest land remains with the legal owner, then this is an indication that the contract is simply a sale of inventories (the growth of which remains an activity of the legal owner). If the management of the forest land during the period of the contract is with the exploiter, then this is an indication that the contract is a forest land leasing (the growth of the timber during the period of the contract is an activity of the exploiter).
651. Under certain circumstances, an ex post other change in volume (in one direction or the other) may be needed at the end of the contract if the forest (in terms of work-in-progress volume) is given back in a different status (with more or less volume of trees) from the one it was given at the beginning of the contract, and this difference is not compensated somehow (for example in monetary terms).
Source: Workbook: subsoil assets, Split-asset calculations worksheet.
652. This section discusses the SNA sequences of economic accounts (current accounts, accumulation accounts, and balance sheets), based on the examples from the four accompanying workbooks. To illustrate the impacts of the changes, the 2008 SNA and 2025 SNA sequences are compared. Breakdowns are shown for the two most relevant national accounts sectors: S13 general government and S11 non-financial corporations (the sector of the natural resource extractors (producers).8
The decision made more than 30 years ago by Mexican authorities to address the economic quantification of environmental damage associated with economic activity was basically due to three institutional factors: the progress in the development of systematically ordered economic information (Mexican System of National Accounts (SCNM, by its Spanish acronym)); the international collaboration mechanisms (World Bank, United Nations); and the recognition and concern for environmental pressures. The commitment of the United Nations Statistics Division and the World Bank to complete jointly with the National Institute of Statistics and Geography (INEGI, by its Spanish acronym) the first environmental accounting scheme in 1991 is highlighted, which included both the main macroeconomic variables derived from the SCNM and data on the impact of productive activities on the environmental context.
The publication in 1988 of the General Law of Ecological Balance and Environmental Protection (LGEEPA, by its Spanish acronym) is also noteworthy, which demands the quantification of the cost of environmental pollution and the depletion of natural resources caused by economic activities to calculate the Environmentally Adjusted Net Domestic Product (PINE by its Spanish acronym) and its integration into the SCNM.
To integrate environmental aspects into the accounting framework, it is necessary to consider macroeconomic variables such as Gross Domestic Product (GDP) and Consumption of Fixed Capital (CFC), to obtain a measure of Net Domestic Product (NDP). In addition to being an important macroeconomic indicator that considers the wear and tear of fixed assets, is the variable on which adjustments derived from quantitative changes in natural resources and the environment are made, to obtain the PINE.
Moreover, to construct the PINE, environmental accounting in Mexico includes the following elements covering both the depletion of natural resources and environmental degradation: depletion of hydrocarbons (oil and gas); loss of timber forest resources; depletion of groundwater; soil degradation; water pollution; urban solid waste; and air emissions. The first three topics refer to the depletion of natural resources and the remaining four are related to environmental degradation.
Calculations are carried out in two phases. First, depletion and degradation are estimated in physical units such as cubic meters of water, barrels of oil, etc. Second, the economic costs associated with depletion and degradation are estimated through different valuation techniques. Once the economic values are consolidated, the PINE is obtained as follows:
Equation 6.2
Where is Environmentally Adjusted Net Domestic Product; is Gross Domestic Product, is Consumption of Fixed Capital (associated with the economic assets produced), is Depletion cost, and is Degradation cost.
Particularly, the costs for depletion are the monetary estimates that express the wear or loss of natural resources (equivalent to depreciation), due to their use in the production process. In 2022, the Dep was equivalent to 0.48% of the national GDP of Mexico.
Concerning the depletion of groundwater, the aquifers of the country that are subject to water stress are identified; that is, those in which the amount of water extracted for economic activities is greater than their recharge volume. The cost of their depletion is derived from a shadow pricing technique (as mentioned in SEEA Water), using information from the SCNM and the economic censuses related to the production account of the water operating agencies.
Source: INEGI. Environmental accounts of Mexico
Regarding the depletion of hydrocarbons, the costs for depletion are estimated through the net rent method, which refers to the net income derived from the economic use of the resource, for which the production costs associated with the extractive activity (intermediate consumption, fixed capital consumption, wages to employees, production taxes, and extraction rights) are deducted from the gross income. All variables come from the SCNM.
For timber forest resources, the replacement cost technique is used, which considers the costs of reforestation considering all its stages until reaching the size at which the resources can be economically utilised (minimum 15 years).
Source: INEGI. Environmental Accounts of Mexico.
Finally, the costs associated with environmental degradation are based on the minimum costs of restoring or preventing further damage to the environment caused by economic activities. For example, the cost associated with air emissions refers to the minimum amount required to avoid and/or reduce emissions through the implementation of technological solutions such as installing filters. The costs of soil degradation, water pollution, and the generation of urban solid waste are based on similar techniques.
For the implementation of the 2025 SNA, Mexico is planning to review its methods for estimating depletion and degradation.
6.6.1. Subsoil assets
653. Table 6-3 shows the 2025 sequence of economic accounts for our workbook example of subsoil assets. Table 6-4 shows the 2008 sequence of economic accounts for our workbook example of subsoil assets. The key differences are:
Production and generation of earned income (formerly generation of income) accounts: GDP is the same, but in the 2025 SNA the NDP value is lower (-219 in our example) due to the inclusion of depletion as a cost of production.
Allocation of earned income (formerly allocation of primary income) account: the depletion borne by the legal owner (S13), which represents a transfer to the producer (S11), is visible for the first time in the 2025 SNA sequence of economic accounts (recorded as a negative revenue of -19 for government and a negative expenditure of -19 for the producer in our example).10 Also, Net National Income (NNI) is lower (-21).
Use of income (formerly use of disposable income) account: net saving is lower in the 2025 SNA (-21 in our example), with both sectors affected but general government more so than non-financial corporations (-19 compared with -2).
Accumulation accounts: there is no impact on net lending/borrowing or transactions in financial assets, but in the 2025 SNA the recording, other changes in volume does not include depletion (as it does in the 2008 SNA) and does include transfers from government to producers of the producer’s share of the split assets at the start of the period; in the 2008 SNA, the asset value stays with government.
Balance sheet: total net worth (opening and closing) is the same, but the sectoral allocation of the closing stocks differs, with S11 having larger net worth in the 2025 sequence.
6.6.2. Renewable energy resources
654. Workbook: renewable energy resources, worksheet 2025 SNA Sequence of Accounts shows the 2025 sequence of economic accounts for our workbook example of renewable energy resources, while worksheet 2008 SNA Sequence of Accounts shows the 2008 sequence of economic accounts. The key differences are:
Production and generation of earned income (formerly generation of income) accounts: GDP and NDP are the same as no depletion (or regeneration) is possible for renewable energy resources (in the 2025 presentation of the sequence of economic accounts in the workbook, the depletion lines are set to zero).
Accumulation accounts: in the 2025 SNA other changes in volume includes transfers from government to producers of the producer’s share of the split assets at the start of the period whereas in the 2008 SNA the asset value was not recorded.
Balance sheet: total net worth (opening and closing) is larger in the 2025 SNA due to the recognition of renewable energy resources.
6.6.3. Timber resources and forest land
655. Workbook: timber resources and forest land, 2025 SNA Sequence of Accounts contains the full 2025 sequence of economic accounts recording of the timber resources and forest land example. Workbook: timber resources and forest land, 2008 SNA Sequence of Accounts contains the full 2008 sequence of economic accounts recording of the timber resources and forest land example, where it is assumed that species A was considered cultivated according to the 2008 SNA and species B non-cultivated.
656. Compilers should note that for the accumulation accounts and balance sheet, the Sequence of accounts 2008 SNA worksheet in the Workbook: timber resources and forest land links to an auxiliary worksheet showing the monetary asset accounts compiled according to the methods for estimating cultivated and non-cultivated forest land in the 2008 SNA. The cells linking from the Sequence of accounts 2008 SNA worksheet to this auxiliary worksheet are highlighted in orange.
657. Key differences between the 2008 and 2025 SNAs are the following:
Production and generation of earned income (formerly generation of income) accounts: the output recorded is different because in 2008 SNA the output consists of natural growth of Species A and harvest (removals) for Species B, while in the 2025 SNA the output for Species B also consists of the natural growth. In our example, GDP according to the 2025 SNA is lower (-19).11 NDP according to 2025 SNA presentation is lower (-22) partly due to the lower GDP and partly due to the inclusion of costs of depletion.
Allocation of earned income (formerly allocation of primary income) account: the depletion borne by government (S13), which represents a transfer to the producer (S11), is visible for the first time in the 2025 SNA sequence of economic accounts (a transfer of -2 in our example). Also, Net National Income (NNI) is lower (-22).
Use of income (formerly use of disposable income) account: net saving is lower in the 2025 SNA (-22 in our example), with both sectors affected but non-financial corporations more so than general government (-20 compared with -2).
Accumulation accounts:
In the capital account, work-in-progress for timber resources is included in the sequence of accounts (in contrast with the other natural resources in this compilation guide). The numbers are different in the 2008 and 2025 SNA presentations, reflecting the differences in scope of cultivated assets: in the 2008 SNA, work-in-progress is only included for Species A, whereas in the 2025 SNA work-in-progress is recorded for both species.
In the other changes in volume of assets account, the 2025 SNA presentation includes transfers from government to producers of the producer’s share of the split assets (the forest land, the work-in-progress remains with the legal owner) at the start of the period, whereas in the 2008 SNA the asset value (of the forest land) stays with government.
Balance sheet: both total net worth and the sectoral allocation of the opening and closing stock values differs between the 2008 SNA and the 2025 SNA. To obtain 2008 SNA-consistent asset values, values for Species A and B are calculated in the auxiliary worksheet. Species B is valued based on sales of harvested timber as output (instead of the net increment) in the resource rent calculation. Species A is valued as in the 2025 SNA approach.
6.6.4. Fish resources
658. Workbook: fish resources, worksheet 2025 SNA Sequence of Accounts shows the 2025 sequence of economic accounts for our workbook example of fish resources, while worksheet 2008 SNA Sequence of Accounts shows the 2008 sequence of economic accounts. The key differences are:
Production and generation of earned income (formerly generation of income) accounts: GDP is the same, but the 2025 SNA NDP value is lower (-62) due to the recording of depletion as a cost of production.
Allocation of earned income (formerly allocation of primary income) account: the depletion borne by government (S13), which represents a transfer to the producer (S11), is visible for the first time in the 2025 SNA sequence of economic accounts (a transfer of -25 in our example). Also, Net National Income (NNI) is lower (-62), with non-financial corporations affected more than general government.
Use of income (formerly use of disposable income) account: net saving is lower in the 2025 SNA (-62 in our example), with both sectors affected but non-financial corporations more so than general government (-37 compared with -25).
Accumulation accounts: in the 2025 SNA other changes in volume includes transfers from government to producers of the producer’s share of the split assets at the start of the period, whereas in the 2008 SNA the asset value stays with government.
Balance sheet: total net worth (opening and closing) is the same, but the sectoral allocation of the closing stocks differs, with S11 having much larger net worth in the 2025 sequence.z
Note: * Some 2025 SNA codes are still under discussion - included here are proposals at the time of writing.
** This is a one-off transfer at the start, when the government is deemed to have transferred the asset, which will not be repeated in future periods
Source: Workbook: subsoil resources, 2025 SNA Sequence of Accounts.
Source: Workbook: subsoil resources, 2008 SNA Sequence of Accounts.
Calculating monetary asset accounts (and depletion cost) in volume terms (Section 6.2)
In case of a single homogeneous natural asset, the volume measure equals the evolution of the physical quantity in the ground.
In the case of different types of natural resources, an aggregation procedure must be identified to construct a volume index across different types of natural assets, such as the index proposed by Schreyer and Obst (2015[2]).
If no physical asset account is available (for example for fish resources), compilers should first estimate opening and closing stocks (in constant prices), which after dividing (and averaging) by their respective asset lives at the beginning and end of the accounting period, provide a constant price estimate of depletion.
Backcasting (Section 6.3)
The NPV estimate is to be considered a best estimate at the time it is made and is always forward looking.
Monetary values should not be revised in retrospect as a result of changes in physical estimates, but it is recommended to always use the most up-to-date national accounts data when calculating resource rent and asset values.
Quarterly estimates of depletion (Section 6.4)
Ideally, quarterly estimates of depletion should be compiled in the same way as annual estimates, however this may not be feasible due to lack of data.
For the quarterly estimation of depletion, it is recommended in the standard approach to apply to the extent possible a similar interpolation (or temporal disaggregation) method as used for estimating depreciation.
Another possibility would be to apply the average ratio of depletion to output of previous periods (preferably using the same number of years as used for smoothing).
References
[3] De Haan, M. and J. Haynes (2019), About natural gas and dwellings in Groningen, Melbourne, 7-10 October 2019, https://seea.un.org/sites/seea.un.org/files/paperhaanhaynesllg2019_v1.0.pdf.
[4] OECD (2009), Measuring Capital - OECD Manual 2009: Second edition, OECD Publishing, Paris, https://doi.org/10.1787/9789264068476-en.
[2] Schreyer, P. and C. Obst (2015), “Towards Complete Balance Sheets in the National Accounts: The case of Mineral and Energy Resources”, OECD Green Growth Papers, No. 2015/2, OECD Publishing, Paris, https://doi.org/10.1787/5js319256pvf-en.
[1] World Bank (2024), The Changing Wealth of Nations. Revisiting the Measurement of Comprehensive Wealth, International Bank for Reconstruction and Development / The World Bank, https://www.worldbank.org/en/publication/the-changing-wealth-of-nations.
← 1. It should be noted that at the time of finalising the guide, some of the codes associated with the classification hierarchies of the 2025 SNA were still under review and may undergo change. Users are advised to consult the final published version of the SNA when it becomes available.
← 2. SEEA Energy §6.57: “Volume measures of mineral and energy resources may be compiled to assist in the analysis of the changes in mineral and energy resources over time. Removal of the effect of a price change may be carried out for either of two main purposes: (a) to provide an indicator of the purchasing power of mineral and energy resources, that is, an estimate of the capacity of a set of resources to be used to acquire a given set of goods and services; or (b) to assess whether there has been a change in the underlying aggregate physical stock of several mineral and energy resources. It may be important for both purposes to be considered when an aggregate analysis of the wealth of a country is being undertaken, or when the relative importance of mineral and energy resources compared with other economic and social assets is being assessed.”
← 3. There is no depletion for timber resources, which is counted as work-in-progress.
← 4. Alternative 1 (as can be seen from the Workbook (Subsoil assets): volume terms, generally provides estimates that are closer to the preferred approach of using the development of physical volumes.
← 5. This discussion refers to “extraction” and “discoveries” because the example is for subsoil assets. As shown in Chapters 3, 4 and 5 the lines of the physical asset account vary according to the type of natural resource. For example, the equivalent of extraction for timber resources is “removals” and for fish is “landings” (see Table 3-1).
← 6. Annual Revision of the National Income and Product Accounts: Annual Estimates for 2005–2007 and Quarterly Estimates for 2005:I–2008:I (bea.gov) (p.18).
← 7. Examples of methods used are:
Australia applies “Linear interpolation and extrapolation are used to estimate quarterly consumption of fixed capital.” (Sources and methods - Quarterly | Australian Bureau of Statistics (abs.gov.au)
Belgium: “There is no quarterly estimate of the fixed capital stock. Quarterly consumption of fixed capital is therefore merely derived from the annual figure by a simple smoothing method, which is perfectly suited to this type of aggregate that moves in very regular patterns.” Comptes nationaux trimestriels de la Belgique (nbb.be).
Germany: “The distribution to quarters is done by using an empirical formula.” Quarterly national accounts inventory based on ESA 2010 methodology - FS 18, Series S.31 (destatis.de).
Portugal: applies an “econometric method” (https://ec.europa.eu/eurostat/documents/24987/4253464/PT-QNA-Inventory-ESA95.pdf/43888445-a08a-44e1-be1a-e04c98ef81a6).
← 8. In the case of household production of renewable energy or household extraction of timber or fish resources, compilers may wish to produce a separate worksheet for the 2025 SNA sequence of economic accounts replacing the column for S11 with a column for S14 household sector. In this case, GOS (code B2g) would be replaced with GMI (code B3g), NOS (B2n) with NMI (B3n) and depreciation on GOS (P51depr1) with depreciation on GMI (P51depr2).
← 9. Some differences may be due to rounding. The differences mentioned here are based on unrounded numbers when doing the comparison, however when looking at the Tables the difference would be 69-47 = 22.
← 10. The recording of depletion in the allocation of earned income account as a negative expenditure of the extractor and a negative revenue for the legal owner, differs from the SEEA CF (Table 5.10), which records it as a positive resource (=revenue) for the extractor and a positive use (=revenue) for the legal owner. The logic of the 2025 SNA is that this recording better shows depletion as offsetting the payment (and receipt) of rent.
← 11. This is a result in our specific example. GDP could also be higher if different numbers were chosen.