NBS-OECD Workshop on National Accounts 6-10 November 2006 Measuring Capital and Capital Services: An Overview Paul Schreyer OECD 1 Purpose of capital measurement 2 main purposes: • Capital as a storage of wealth • Capital as a source of productive services The two purposes correspond more or less to • Capital in the balance sheets and in the income side of the national accounts, e.g., value of fixed assets, depreciation, net and gross income… Relevant questions: what is the value of wealth in the economy? Is current income sustainable? 2 Purpose of capital measurement • Capital in the production side of the national accounts Relevant questions: capital and multi-factor productivity, growth accounting, competitiveness • In the SNA93, no explicit recognition of capital in the production account • In revision to SNA 93, explicit recognition of capital income and capital services in the production account 3 Stocks and flows – an integrated approach • Key objective of new capital manual: present integrated and consistent approach towards capital measurement to link relevant flows and relevant stocks: • Investment • Depreciation • Capital services • Net stock • Gross stock • Productive stock 4 System of capital in the SNA93 Age-price Net value added function Net stock CFC Gross stock Investment Retirement function 5 System of capital in the new SNA Age-price Net value added function Net stock CFC Return on capital User costs Gross stock Investment Retirement function Age-efficiency Productive stock Capital services function 6 Stocks and flows – an overview Income and wealth perspective Basic flow Aggregation across assets different age based on Investment Production and productivity perspective Investment of Depreciation profile (Age-price Age-efficiency profile profile) Resulting stock for each class of Net capital stock by asset type assets Productive stock by asset type Derived flow Capital services by type of asset Depreciation Aggregation across different Market prices classes of assets based on Rental prices or user costs Resulting stocks Total net capital stock Total productive stock Derived measure Balance sheet entry, national Total capital services, multiwealth, net measures of income factor productivity 7 Asset market equilibrium condition Central economic relationship that links income and production perspective Walras (1874); Boehm-Bawerk (1888) • Stock value of an asset = discounted stream of future rental payments that the asset is expected to yield P0t: price of new asset purchased at the beginning of period t fnt: nominal rental payable at beginning of period t (1+rt): nominal discount factor P0t=f0t+1/(1+rt) + f1t+2/(1+rt)2 + f2t+3/(1+rt)3+… 8 Asset market equilibrium condition (2) In a functioning market, purchase price of an asset equals the discounted stream of expected rentals Purchasers will buy asset of flow of rental implies at least a rate of return that is as large as rt rt can also be considered the opportunity cost of investing in the asset = the return that the market would pay for investment of similar risk Central equation for integrated system of stocks and flows of capital 9 Rentals and asset prices – numerical example (1) Assume: asset with • Service life of 8 years • Discount rate 5 % • Rental for a new asset is 10$ • For simplicity, no general inflation • Price of new asset and price of rentals are expected to rise by 2% per year: fnt+1=fnt*1.02 • Productive services of the asset decline by a constant amount over its service life: linear age-efficiency pattern 10 Rentals and asset prices – numerical example (2) 10*0.88*1.02 =8.93 Year (t) Rental Rental price Ageprice discounted efficiency beginning to of period beginning of year 1 1 100% 2 88% 10.00 3 75% 8.93 4 63% 7.80 5 50% 6.63 6 38% 5.41 7 25% 4.14 8 13% 2.82 9 0% 1.44 10 0.00 Price of asset beginning of year 9.52 8.10 6.74 5.46 4.24 3.09 2.00 0.97 0.00 40.12 10.0/1.05=9.52 11 Rentals and asset prices – numerical example (3) Rental price discounted to beginning of year Year (t) Rental price Ageefficiency beginning of period 100% 1 10.00 88% 2 8.93 75% 3 7.80 63% 4 6.63 50% 5 5.41 38% 6 4.14 25% 7 2.82 13% 8 1.44 0% 9 0.00 10 Price of asset beginning of year 1 9.52 8.10 6.74 5.46 4.24 3.09 2.00 0.97 0.00 40.12 2 8.50 7.08 5.73 4.45 3.24 2.10 1.02 0.00 32.12 3 4 5 7.43 6.02 4.68 3.41 2.21 1.07 0.00 24.81 6.32 4.91 3.58 2.32 1.13 0.00 18.24 5.15 3.76 2.43 1.18 0.00 12.52 8 7 6 3.94 2.55 1.24 0.00 7.74 2.68 1.30 0.00 3.98 7.80/1.052 =7.08 12 1.37 0.00 1.37 Rentals and asset prices – numerical example (4) This example also shows a very important link between ageefficiency profile and the age-price profile For a given rate of interest, a given rate of price change of new assets, there will be exactly one sequence of asset prices for each age-efficiency profile Consider the following price history of an asset 13 Rentals and asset prices – numerical example (5), Price history of asset Year (t) 1 2 3 4 5 6 7 8 9 0 1 2 40.12 40.92 41.74 42.57 43.43 44.29 45.18 46.08 47.01 32.12 32.77 33.42 34.09 34.77 35.47 36.18 36.90 24.81 25.30 25.81 26.32 26.85 27.39 27.94 Age of asset 3 4 18.24 18.61 18.98 19.36 19.75 20.14 12.52 12.77 13.03 13.29 13.56 5 6 7 8 7.74 7.89 8.05 8.21 3.98 4.06 4.14 1.37 1.39 0.00 Diagonal price movement: total change in value of asset between two years e.g. 40.12-32.12 = 8 •Vertical movement: price change of new asset (2%) = 40.92-40.12=0.80 •Horizontal movement: price difference due to age = 40.92-32.12=8.80 14 Rentals and asset prices – numerical example (6), Age-price profile Year (t) 1 2 3 4 5 6 7 8 9 2 Age of asset 3 4 0 1 5 6 7 8 40.12 40.92 41.74 42.57 43.43 44.29 45.18 46.08 47.01 32.12 32.77 33.42 34.09 34.77 35.47 36.18 36.90 24.81 25.30 25.81 26.32 26.85 27.39 27.94 18.24 18.61 18.98 19.36 19.75 20.14 12.52 12.77 13.03 13.29 13.56 7.74 7.89 8.05 8.21 3.98 4.06 4.14 1.37 1.39 0.00 78.50% 78.50% 78.50% 78.50% 78.50% 78.50% 78.50% 78.50% 59.43% 59.43% 59.43% 59.43% 59.43% 59.43% 59.43% 42.85% 42.85% 42.85% 42.85% 42.85% 42.85% 28.84% 28.84% 28.84% 28.84% 28.84% 17.47% 17.47% 17.47% 17.47% 8.82% 8.82% 8.82% 2.97% 2.97% 0.00% 32.12/40.92=0.785 15 Rentals and asset prices – numerical example (7) Note: Age-price profile does not depend on time here because age-efficiency profile is not time-dependent and because the expected rates of asset price change and discount factors are given for any point in time However, as historical time moves on, it may well be that discount factors or price expectations change, in which case the age-price profiles of all assets would be affected. 16 Rentals and asset prices – numerical example (8), linear age-efficiency profile Age Age-efficiency profile 0 1.00 1 0.88 2 0.75 3 0.63 4 0.50 5 0.38 6 0.25 7 0.13 8 0.00 Age-price profile 1.00 0.79 0.59 0.43 0.29 0.17 0.09 0.03 0.00 1 0.8 0.6 0.4 0.2 0 1 2 3 4 5 Age-efficiency profile 6 7 8 9 10 Age-price profile 17 Rentals and asset prices – numerical example (9), constant age-efficiency profile Age Age-efficiency profile 0 1.00 1 1.00 2 1.00 3 1.00 4 1.00 5 1.00 6 1.00 7 1.00 8 1.00 Age-price profile 1.00 1.00 0.89 0.77 0.65 0.53 0.40 0.27 0.14 1 0.8 0.6 0.4 0.2 0 1 2 3 4 5 Age-efficiency profile 6 7 8 9 10 Age-price profile 18 Rentals and asset prices – numerical example (10), geometric age-efficiency profile Age Age-efficiency profile 0 1.00 1 0.78 2 0.60 3 0.47 4 0.37 5 0.28 6 0.22 7 0.17 8 0.13 Age-price profile 1.00 0.78 0.60 0.47 0.37 0.28 0.22 0.17 0.13 1 0.8 0.6 0.4 0.2 0 1 2 3 4 5 Age-efficiency profile 6 7 8 9 10 Age-price profile 19 Rentals and asset prices – numerical example (11), hyperbolic age-efficiency profile Age Age-efficiency profile 0 1.00 1 0.93 2 0.86 3 0.77 4 0.67 5 0.55 6 0.40 7 0.22 8 0.00 Age-price profile 1.00 0.82 0.66 0.50 0.36 0.23 0.12 0.04 0.00 1.20 1.00 0.80 0.60 0.40 0.20 0.00 0 1 2 3 4 Age-efficiency profile 5 6 7 8 Age-price profile 20 Retirement and survival functions (1) • Assets in a cohort are unlikely to retire all at the same moment • Typically, there is a retirement distribution around an average retirement age • To construct the age-efficiency function of a cohort, the age-efficiency function for a single asset has to be combined with a retirement distribution • This is shown in the following slides 21 Retirement and survival functions (2) • Probability density function of retirement: shows the (marginal) probability for an asset to retire at age T • For simplicity, log-normal distribution Normal distribution, average service life = 8 years 0.25 0.20 0.15 0.10 0.05 0.00 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 22 Retirement and survival functions (3) • Call the probability that an asset retires at age T, FT • In our example with a linear age-efficiency function gs, we had gs=1-s/T. • For a single asset, the service life was assumed T=8 • With a retirement distribution, for each age s, there is a possibility that the asset retires at age s, or at age s+1 etc. • Calculate an average, with probability weighting where Tm is the maximum service life: hs= ∑T=sTm[1-s/T]*FT • This creates a new age-efficiency profile for the cohort that reflects both efficiency loss and retirement {hs} 23 Retirement and survival functions (4), ageefficiency profiles gs 0.938 0.875 0.813 0.750 0.688 0.625 0.563 0.500 0.438 0.375 hs 0.889 0.778 0.667 0.557 0.448 0.342 0.243 0.158 0.091 0.046 1 2 3 4 5 6 7 8 9 10 s--> 1.000 0.800 0.600 0.400 0.200 0.000 1 2 3 4 5 6 Single asset • 7 8 9 10 11 12 13 14 15 16 Cohort with retirement distribution hs is non-linear even with linear gs! 24 Retirement and survival functions (5) A special case: one-hoss shay • Suppose a class of assets follows a one-hoss shay pattern of efficiency loss: efficiency is constant until the asset retires • Then, the combined age-efficiency/retirement pattern {hsG} becomes hsG= ∑T=sTmFT, i.e., only a retirement pattern. • More precisely, hsG is the cumulative probability density function that varies from h0G=1 for a new asset to hTmG=0 • It is now possible to construct the gross capital stock on the basis of the perpetual inventory method: • Gross capital stock = sum of past investments of a class of assets, with cohorts weighted by the retirement pattern {hsG} 25 Retirement and survival functions (6) A special case: one-hoss shay 1.200 1.000 0.800 0.600 0.400 0.200 0.000 1 2 3 4 5 6 Single asset 7 8 9 10 11 12 13 14 15 16 Cohort with retirement distribution 26 Retirement and survival functions (7) Gross capital stock • Gross capital stock = sum of past investments of a class of assets, with cohorts weighted by the retirement pattern {hsG} • Gross capital stock = stock of assets surviving from past investments that ignores deterioration of assets and considers past investment ‘as new’ - only retirement is taken into account • Although the gross capital stock is often calculated in practice, it serves mainly as an intermediate step towards measuring depreciation and net stocks rather than as an analytical measure in itself. • Note: net stocks and depreciation can but do not have to be calculated via the gross stock. In fact, the usefulness of the gross stock is relatively limited. • Some countries (eg United States) do not publish gross stocks any more – they restrict themselves to net stocks and productive stocks (see later) 27 Retirement and survival functions (8) Gross capital stock Year (t) Investment at historical prices 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 500 800 1000 600 500 700 750 900 1200 1000 1100 1200 1100 1000 900 800 Price index (new) capital goods 1.000 1.020 1.040 1.061 1.082 1.104 1.126 1.149 1.172 1.195 1.219 1.243 1.268 1.294 1.319 1.346 Investment in prices of year 16, weighted Investment with in prices of Retirement retirement year 16 pattern pattern 672.9 1055.6 1293.6 760.9 621.7 853.3 896.3 1054.5 1378.4 1126.2 1214.5 1298.9 1167.3 1040.4 918.0 800.0 0.0060 0.0225 0.0666 0.1584 0.3083 0.4998 0.6912 0.8411 0.9330 0.9770 0.9936 0.9984 0.9995 0.9997 0.9998 1.0000 4.0 23.8 86.1 120.6 191.7 426.4 619.6 886.9 1286.0 1100.3 1206.7 1296.9 1166.8 1040.1 917.8 800.0 Note three types of valuation of stocks: •Historical prices = valuation in terms of prices of the year of acquisition •Constant prices = valuation in terms of a base year •Current prices = special case of constant prices = valuation in terms of the current (typically latest) year 28 Gross stock at (current) prices of year 16 11173.6 Net or wealth stocks (1) • Net capital stock or wealth stock = market value of assets • Net capital stock = stock of assets surviving from past investments that has been corrected for retirement and for loss in value due to ageing • Net capital stock offers a wealth perspective. It is the capital stock that shows up in the balance sheets of the national accounts. • Calculation of net stocks: 2 possibilities: • Directly, as sum of past investments, weighted by ageprice profile • Derived from gross stock and depreciation 29 Net or wealth stocks (2) • Starting point: age-price profile, derived from combined age-efficiency & retirement profile 1.20 1.00 0.80 0.60 0.40 0.20 0.00 0 1 2 3 4 5 6 7 8 Age-efficiency & retirement profile 9 10 11 12 13 14 15 16 Age-price & retirement profile 30 Net or wealth stocks (3) Year (t) Investment at historical prices 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 500 800 1000 600 500 700 750 900 1200 1000 1100 1200 1100 1000 900 800 Price index (new) capital goods 1.000 1.020 1.040 1.061 1.082 1.104 1.126 1.149 1.172 1.195 1.219 1.243 1.268 1.294 1.319 1.346 Investment in prices of year Combined 16, weighted Investment Age-price + with in prices of retirement retirement year 16 pattern pattern 672.9 1055.6 1293.6 760.9 621.7 853.3 896.3 1054.5 1378.4 1126.2 1214.5 1298.9 1167.3 1040.4 918.0 800.0 0.0000 0.0001 0.0006 0.0020 0.0060 0.0154 0.0338 0.0656 0.1141 0.1816 0.2691 0.3768 0.5042 0.6509 0.8163 1.0000 Net stock 31/Dec/year 16 at (current) prices of year 16 0.0 0.1 0.7 1.5 3.7 13.1 30.3 69.2 157.3 204.5 326.9 489.4 588.5 677.2 749.4 800.0 4111.9 31 Depreciation (Consumption of fixed capital) (1) •Depreciation is the loss in value of an asset or a group of assets as they age •A flow concept •Economic meaning: deduction from gross income to account for the loss in capital value owing to the use of capital goods in production •SNA definition: « the decline, during the course of the accounting period, in the current value of the stock of fixed assets owned and used by a producer as a result of physical deterioration, normal obsolescence or normal accidental damage. » •Excluded: value losses due to acts of war or as a consequence of 32 exceptional events such as major natural disasters Depreciation (Consumption of fixed capital) (2) Note: •Depreciation must be measured with reference to a given set of prices, ie the average prices of the period •“Used by producer” includes assets that are kept idle for whatever reasons •“Normal obsolescence” is included in depreciation but not “abnormal obsolescence”. Example: scrapping of energyintensive machines following an oil-price shock 33 Computing depreciation (1) Two avenues: directly and indirectly via net stock Direct computation: main tool: age-price profile and investment series •Rate of depreciation of an s-year old asset = price difference between an s-year old asset and an s+1 year old asset divided by price of an s-year old asset: t t P P d st s t s 1 Ps {P0t, P1t, P2t,…} is the age-price profile, so dst can be derived directly 34 Computing depreciation (2) •When applied to past investment, depreciation rates apply in a cumulative way: •Depreciation for a new capital good: d0It •Depreciation for a one-year old capital good: d1(1-d0)It-1 •Depreciation for a one-year old capital good: d2(1-d1)(1-d0)It-2 •Etc. Total depreciation = d0It + d1(1-d0)It-1 + d2(1-d1)(1-d0)It-2 + … Note: investment {It, It-1,…} is expressed in constant prices of a particular base year, therefore total depreciation is also in prices of this base year. 35 Computing depreciation (3) Age-price profile Age 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Depreciation rates Pst Pst1 ds Pst 46.01 37.56 29.94 23.19 17.33 12.38 8.36 5.25 3.02 1.56 0.71 0.28 0.09 0.03 0.01 0.00 0.00 1.00 0.82 0.65 0.50 0.38 0.27 0.18 0.11 0.07 0.03 0.02 0.01 0.00 0.00 0.00 0.00 0.00 0.18369 0.20268 0.22538 0.25269 0.28564 0.32517 0.37181 0.42526 0.48412 0.54602 0.60813 0.66786 0.72348 0.77489 0.82538 0.88736 1.00000 Depreciation profile D s d s (1 d s 1 )(1 d s 2 )...(1 d 0 ) 0.1837 0.1655 0.1467 0.1274 0.1076 0.0875 0.0675 0.0485 0.0317 0.0185 0.0093 0.0040 0.0014 0.0004 0.0001 0.0000 0.0000 (46.0137.56)/46.01=0.184 36 Computing depreciation (4) Year (t) Investment at historical prices 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 500 800 1000 600 500 700 750 900 1200 1000 1100 1200 1100 1000 900 800 Price index (new) capital goods 1.000 1.020 1.040 1.061 1.082 1.104 1.126 1.149 1.172 1.195 1.219 1.243 1.268 1.294 1.319 1.346 Investment in prices of year 16 672.9 1055.6 1293.6 760.9 621.7 853.3 896.3 1054.5 1378.4 1126.2 1214.5 1298.9 1167.3 1040.4 918.0 800.0 Investment in prices of year 16, weighted with Depreciation depreciation profile profile 0.0000 0.0001 0.0004 0.0014 0.0040 0.0093 0.0185 0.0317 0.0485 0.0675 0.0875 0.1076 0.1274 0.1467 0.1655 0.1837 Depreciation during period 16 at (current) prices of year 16 0.0 0.1 0.6 1.1 2.5 8.0 16.6 33.5 66.9 76.1 106.3 139.8 148.7 152.6 151.9 147.0 1051.5 37 Computing depreciation (5) Net capital stock for period 17 at prices of period 16 Year (t) Investment at historical prices 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 500 800 1000 600 500 700 750 900 1200 1000 1100 1200 1100 1000 900 800 1000 Price index (new) capital goods 1.000 1.020 1.040 1.061 1.082 1.104 1.126 1.149 1.172 1.195 1.219 1.243 1.268 1.294 1.319 1.346 1.373 Investment in prices of year Combined 16, weighted Investment Age-price + with in prices of retirement retirement year 16 pattern pattern 672.9 1055.6 1293.6 760.9 621.7 853.3 896.3 1054.5 1378.4 1126.2 1214.5 1298.9 1167.3 1040.4 918.0 800.0 980.4 Net stock 31/Dec/year 17 at prices of year 16 0.0000 0.0001 0.0006 0.0020 0.0060 0.0154 0.0338 0.0656 0.1141 0.1816 0.2691 0.3768 0.5042 0.6509 0.8163 1.0000 0.0 0.2 0.4 1.2 5.1 13.8 35.7 90.4 128.5 220.6 349.6 439.8 524.5 597.5 653.0 980.4 4040.8 38 Computing depreciation (6) Indirect way of computing depreciation via net stocks and the following identity: Net stock 31/Dec/year 16 + Gross investment during year 17 - Depreciation during year 16 Net stock 31/Dec/year 17 4111.9 980.4 1051.5 4040.8 Note: specific lags in this identity (depreciation year 16) disappear when everything is formulated in mid-year valuations 39 Computing depreciation (7) Note: depreciation is in prices of period 16 •To obtain depreciation at current prices, apply investment goods deflator between years 16 and 17 • This is also an easy solution to split depreciation into price and volume components – the deflator for depreciation always equals the asset price deflator 40 Computing depreciation (8) Empirical basis for depreciation rates 1. Derived from age-efficiency functions. This raises the issue of how age-efficiency parameters are constructed. Needed: average service lives and retirement distributions surveys or assumptions 2. Measured directly. • Service lives and retirement distributions from surveys, combined with some assumptions about the functional form of age-price functions • Most frequent assumption: linear profile (constant amount of depreciation) Ps/P0=1-s/T 41 Computing depreciation (9) • Geometric profile (constant rate of depreciation): Ps/P0 = (1-)s where = DBR/T DBR: declining balance parameter, often set to equal 2 (“double declining balance”) For example, BEA uses DBR=2.2 for computers, DBR=1.65 for machinery and equipment, DBR=0.9 for structures T: expected mean service life • Econometric estimates based on used asset prices (Hulten Wykoff 1981) 42 Productive stocks and capital services (1) Net stock and depreciation have to do with the value side of capital and income Productive stocks and capital services have to do with the quantity side of capital and its role in production, i.e. as capital input The flow of capital services is normally assumed to be a constant proportion of the productive capital stock The productive stock is the stock of cumulative investment of a particular type, corrected for retirement and efficiency losses, as captured by the age-efficiency and retirement function 43 Productive stocks and capital services (3) Productive stock of asset type i at the beginning of period t+1, and in constant prices of period t: K i , t 1 h 0 I h 1I t t 1 h 2I t 2 h 3I t 3 ... {hs} s=0,1,2,… is the combined age-efficiency/retirement profile By way of the numerical example used earlier, the productive stock is computed as follows: 44 Productive stocks and capital services (4) Year (t) Investment at historical prices 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 500 800 1000 600 500 700 750 900 1200 1000 1100 1200 1100 1000 900 800 Price index (new) capital goods 1.000 1.020 1.040 1.061 1.082 1.104 1.126 1.149 1.172 1.195 1.219 1.243 1.268 1.294 1.319 1.346 Investment in prices of Combined year 16, Ageweighted Investment efficiency + with in prices of retirement retirement year 16 pattern pattern 672.9 1055.6 1293.6 760.9 621.7 853.3 896.3 1054.5 1378.4 1126.2 1214.5 1298.9 1167.3 1040.4 918.0 800.0 0.0001 0.0005 0.0021 0.0071 0.0197 0.0459 0.0914 0.1580 0.2434 0.3420 0.4478 0.5570 0.6674 0.7782 0.8891 1.0000 0.1 0.5 2.7 5.4 12.2 39.2 81.9 166.6 335.6 385.1 543.9 723.5 779.1 809.6 816.2 800.0 45 Productive stock 31/Dec/year 16 at (current) prices of year 16 5501.6 Productive stocks and capital services (5) Example from Australia 180 170 Capital services 160 150 140 130 Net (wealth) capital stock 120 110 100 1986 1988 1990 1992 1994 1996 1998 46 User costs and its elements (1) Price of capital services Productive stock and capital services are the quantity/volume of capital input to production What is the price of capital services? Price of capital services = user costs or rental price Basic idea: how much would an owner of a capital good charge if he rented out the capital good for one period under competitive conditions? The rental price/user cost should cover: • A ‘normal’ net return to the capital owner to account for opportunity costs • Depreciation • Expected revaluation 47 User costs and its elements (10) A reasonable approximation is: u0t = [r*t + d0] P0t. where the user cost is the sum of a real rate of return and depreciation This user cost formula, due essentially to Walras says that the user cost of capital is equal to the anticipated real interest rate plus the anticipated depreciation rate times the beginning of the period stock price of the asset. 48 User costs and its elements (11) There are two broad options (Diewert 1980 and Harper, Berndt and Wood 1989): • Use of an endogenous (internal) rate of return (estimated capital services exactly corresponds to gross operating surplus and the capital element of gross mixed income) • Use of an exogenous (external) rate of return (estimated capital services is unlikely to be exactly equal to gross operating surplus and the capital element of gross mixed income) 49 Scope of assets and capital services • Note: new asset classification proposed in revised SNA • All fixed assets are within the scope of capital services • Some special cases: 1. Research and development – not presently recognised as fixed assets, but SNA revision will bring them into asset scope statistical issues of how to measure R&D stocks, how to deflate them, how to depreciate them 2. Some assets are non-produced but sources of capital services, in particular land (see below for more extensive discussion) 3. Some assets are produced but not fixed inventories should they be part of the scope of capital services? 4; Government assets 50 Valuation (1) Valuation – an issue of practical importance •SNA: flows should be valued at average prices of the period to which they relate •SNA: stocks in the balance sheets should be valued at the prices of the point in time to which they relate •The various flow measures (depreciation, value of capital services) should thus be measured at average prices of the period •When there is a link to stock measures, stock measures should also be valued at average prices of the period for the purposes of carrying out calculations and preserving the link, but not as an entry into the balance sheet 51 Valuation (2) Example: Net stock at the end of year t and at average prices of the year t = Net stock at the beginning of year t, valued at average prices of year t Plus Gross investment during year t at average prices of year t Minus Depreciation during year t at average prices of year t 52 Data requirements Summary of data requirement: •Benchmark estimate for capital stock, eg from capital survey •Time series of investment expenditure by type of asset and by industry •Deflators for investment goods, possibly separate deflators for new and for used assets •Estimates of retirement or survival patterns •Estimates of depreciation rates or age-efficiency rates •Gross operating surplus (by industry) •Split of mixed income into labour and capital part 53 Overall conclusions on capital measurement •Measurement and interpretation of capital has long occupied economists and statisticians •Revision of SNA marks an important step forward in the harmonised treatment of assets and the associated flows in the national accounts •Objective: consistent set of asset-related data with flows and stocks that fit together and that are analytically useful •Capital measurement requires still many assumptions, and national accountants rightly try to minimise assumptions in measurement 54 Overall conclusions on capital measurement (2) •Additional empirical information concerning capital is key to improve quality of estimates and to reduce the number of assumptions studies on depreciation or asset lives Investment in investment goods deflators Capital flow matrices for the economy •Significant movement and willingness to move forward in this domain 55