國民經濟核算體系

國民經濟核算體系 (SNA) 是國民經濟核算的國際標準體系，第一版國際標準於 1953 年釋出。 並隨後釋出了 1968 年修訂版、1993 年修訂版和 2008 年修訂版。 國民經濟核算體系以其各種釋出的版本，經常進行重大的本地調整，已被許多國家採用。它不斷發展，並由聯合國、國際貨幣基金組織、世界銀行、經濟合作與發展組織和歐盟統計局維護。

SNA 的目標是提供一個綜合、完整的賬戶系統，以便對所有重要經濟活動進行國際比較。建議各國以 SNA 為指導構建本國的國民核算體系，以促進國際可比性。然而，遵守國際標準完全是自願的，不能嚴格執行。一些國家（例如法國、美國和中國）使用的系統與國民賬戶體系有很大不同。就其本身而言，這並不是一個主要問題，只要每個系統都提供足夠的資料，這些資料可以根據國民賬戶體系標準進行修改以編制國民賬戶。

SNA 為市場經濟國家使用的核算體系。中國大陸在改革開放後，自 1992 年完整引入該核算體系，取代之前的《國民經濟平衡表體系》（MPS），並與聯合國國民經濟核算體系（UNSNA）接軌。

資料釋出

成員國的經濟和金融資料用於編制有關生產總值、投資、資本交易、政府支出和對外貿易的年度（有時是季度）資料。結果發表在聯合國年鑑《國民賬戶統計：主要總量和詳細表格》中，該年鑑目前（直至 2008 年修訂版生效）遵循 1993 年的建議。 提供的值以本國貨幣表示。

此外，國家統計局也可能釋出 SNA 型別的資料。更詳細的資料通常可以按需提供。由於國民賬戶資料極易被修改（因為涉及大量不同資料來源、條目和估算過程會影響總量結果），因此不同年份不同出版物針對同一會計期間的總量資料也經常存在差異。由於新的資料來源、統計方法或概念的變化，“最終數字” 可能會被多次追溯修改。每年的修訂程度可能很小，但累積例如十年的修訂後，資料差異可能會顯著改變趨勢。這是研究人員在尋求連貫一致的資料集時應該牢記的事情。

質量和覆蓋範圍

各國國民賬戶資料的質量和全面性各不相同。原因包括：

一些政府在統計研究上投入的資金遠多於其他政府。
一些國家的經濟活動比其他國家更難準確衡量（例如，灰色經濟規模龐大、文盲普遍存在、缺乏現金經濟、由於地理因素或社會政治不穩定而難以獲得調查機會、人員流動性很大）人員和資產 —— 在撒哈拉以南非洲國家尤其如此）。
一些統計機構比其他機構擁有更多的科學自主權和預算自由裁量權，使它們能夠開展其他統計機構因法律、政治或財務原因而無法開展的調查或統計報告。
一些國家（例如荷蘭、德國、英國、波蘭和澳大利亞）在社會統計領域擁有強大的知識（學術或文化）傳統，通常可以追溯到一百年甚至幾百年前，而其他國家（例如正如許多非洲國家一樣，政府最近才開始組織人口普查，而大多數大學也很晚才開始組織人口普查）。重要的是，一個社會是否看到統計的價值，是否廣泛利用統計專業知識用於分析和政策目的，從而對統計行業進行投資。
儘管簽署了國際公約，聯合國幾乎沒有權力強制成員國按照特定標準進行資料統計；作為國際聯盟的成員（例如歐盟、經合組織，或美國），協議要求聯盟成員國必須提供標準化資料集，以進行國家間比較，即使這些標準化資料集可能對組織本身沒有太多用處。因此，可能存在產生國際組織需要的更全面的統計資訊的 “外部激勵”，來激勵部分國家，但這些激勵可能對其他國家沒什麼效果。

SNA 主要賬戶

3.1 SNA 包括以下主要賬戶

the production account (components of gross output)
the primary distribution of income account (incomes generated by production)
the transfers (redistribution) account (including social spending)
the household expenditure account
the capital account
the (domestic) financial transactions account ("flow of funds")
the changes in asset values account
the assets and liabilities account (balance sheet)
the external transactions account (balance of payments)

這些賬戶包括各種附件和子賬戶，還為顯示生產部門之間交易的投入產出表提供了標準。

幾乎所有聯合國成員國都提供收入和產品賬戶，但不一定提供全套標準賬戶或全套資料，以提供標準會計資訊。例如，家庭的標準化資產和負債賬戶幾乎不存在，有待開發。

最近的一項進展是嘗試建立自然資源戰略庫存的標準賬戶。

發展

SNA 繼續得到進一步發展，並定期召開國際會議來討論各種概念和計量問題。

一些例子包括環境資源賬戶的構建、服務貿易和資本存量的計量、保險付款的處理、灰色經濟、股票期權或其他非工資收入形式的員工補償、無形資本

Discussions and updates are reported in SNA News & Notes .

SNA Revisions are documented at the UN Statistics Division site

The 2008 SNA Revision

For the 2008 SNA Revision, the full text is available online: . The OECD provides some overview commentary .

The revision of the 1993 system was coordinated by the Intersecretariat Working Group on National Accounts (ISWGNA) comprising the United Nations Statistics Division (UNSD), International Monetary Fund (IMF), World Bank (WB), Organisation for Economic Co-operation and Development (OECD), Statistical Office of the European Communities (Eurostat) and the United Nations regional commissions.

The ISWGNA working group has its own website under the UN Statistics Division.

對國民賬戶體系的批評

6.1 一般批評

對國民賬戶體系最普遍的批評一直是它的概念沒有充分反映現實世界的相互作用、關係和活動 —— 原因有多種，但主要是因為：

該系統沒有提供特定經濟現象的明確細節，從而表明它們並不真正存在。
假設的估值方案存在問題。
在勇敢地嘗試將所有 “微觀” 商業活動納入一般 “宏觀” 標題下時，必然會導致現實結果的扭曲，因為至少一部分微觀交易不容易符合一般概念標題。
國民賬戶資料並不能解決許多社會問題，因為這些問題確實需要不同型別的資料來解決，例如行為資料、態度資料或身體資料。
國民賬戶資料是由數千個不同的資料系列構建的，並且在首次官方估計釋出後，結果通常會多次修訂。因此，就所使用的測量概念而言，最初的估計很少是完全準確的。此外，早期釋出的資料系列通常也會進行修訂，有時甚至是多年後，因此資料可能永遠不會完全 “最終” 和準確。

6.2 Criticism of GDP

The most popular criticism of national accounts is made against the concept of gross domestic product (GDP).

In part, this criticism of GDP is misplaced, because the fault is not so much with the concept itself. It is useful to have a measure of a country's total net output, and its changes over time – that's better than having no measure at all.

The fault is with the actual use that is made of the concept by governments, intellectuals, and businessmen in public discourse. GDP is used for all kinds of comparisons, but some of those comparisons are conceptually not very appropriate.

GDP measures are frequently abused by writers who neither understand what they mean, how they were produced, nor what they can be validly used for.

Economists like Joseph Stiglitz argue that a measure of "well-being" is needed to balance a measure of output growth.

6.3 Feminist criticism

SNA has been criticised as biased by feminist economists such as Marilyn Waring and Maria Mies because no imputation for the monetary value of unpaid housework, or for unpaid voluntary labor is made in the accounts, even though the accounts do include the "imputed rental value of owner-occupied dwellings" (the market-rents which owner-occupiers would receive if they rented out the housing they occupy). This obscures the reality that market production depends to a large extent on non-market labour being performed.

However, such criticism raises several questions for the statisticians who would have to produce the data:

whether an international standard method of imputation for the value of such services is feasible, given e.g. that the conditions under which the market equivalents for unpaid household services are supplied vary a great deal internationally ;
whether making the imputation would result in truly meaningful, internationally comparable measures;
whether attaching a price to voluntary labor, done primarily by women, itself actually performs an emancipatory or morally propitious function or has a general useful purpose beyond academia.

The intention of those who would like to produce this kind of standard data might be perfectly honorable, but the production of the data has to be practically justifiable in terms of technical feasibility and utility. Attaching an imaginary price to housework might not be the best data to have about housework.

In most OECD countries, statisticians have in recent years estimated the value of housework using data from time use surveys. The valuation principle often applied is that of how much a service would cost, if it was purchased at market rates, instead of being voluntarily supplied. Sometimes an "opportunity cost" method is also used: in this case, statisticians estimate how much women could earn in a paid job if they were not doing unpaid housework. Typically, the results suggest that the value of unpaid housework is close to about half the value of GDP.

Christine Lagarde, the head of the International Monetary Fund, claimed at the IMF World Bank annual meetings in Tokyo in October 2012 that women could rescue Japan's stagnating economy, if more of them took paid jobs instead of doing unpaid care work. A 2010 Goldman Sachs report had calculated that Japan's GDP would rise by 15 percent, if the participation of Japanese women in the paid labour force was increased from 60 percent to 80 percent, matching that of men. The difficulty with this kind of argument is, that domestic and care work would still need to be done by someone, meaning women and men would need to share household responsibilities more equally, or rely on public- or private-sector provided child and eldercare. According to the ILO, there are over 52 million domestic workers in the world, who mostly work for little pay and with little legal protection. They are mainly servants of the wealthy and the middle class.

6.4 Marxist criticism

Marxian economists have criticized SNA concepts also from a different theoretical perspective on the new value added or value product. On this view, the distinctions drawn in SNA to define income from production and property income are rather capricious or eclectic, obscuring thereby the different components and sources of realised surplus value; the categories are said to be based on an inconsistent view of newly created value, conserved value, and transferred value (see also double counting). The result is that the true profit volume is underestimated in the accounts – since true profit income is larger than operating surplus – and workers' earnings are overestimated since the account shows the total labour costs to the employer rather than the "factor income" which workers actually get. If one is interested in what incomes people actually get, how much they own, or how much they borrow, national accounts often do not provide the required information.

Additionally, it is argued by Marxists that the SNA aggregate "compensation of employees" does not distinguish adequately between pre-tax and post-tax wage income, the income of higher corporate officers, and deferred income (employee and employer contributions to social insurance schemes of various kinds). "Compensation of employees" may also include the value of stock options received as income by corporate officers. Thus, it is argued, the accounts have to be substantially re-aggregated, to obtain a true picture of income generated and distributed in the economy. The problem there is that the detailed information to do it is often not made available, or is available only at a prohibitive cost.

US government statisticians admit frankly that "Unfortunately, the finance sector is one of the more poorly measured sectors in national accounts". The oddity of this is, that the finance sector nowadays dominates international transactions, and strongly influences the developmental path of the world economy. So, it is precisely the leading sector in the world economy for which systematic, comprehensive, and comparable data are not available.

6.5 Statisticians' criticisms

Statisticians have also criticized the validity of international statistical comparisons using national accounts data, on the ground that in the real world, the estimates are rarely compiled in a uniform way – despite appearances to the contrary.

For example, Jochen Hartwig provides evidence to show that "the divergence in growth rates of real GDP between the U.S. and the EU since 1997 can be explained almost entirely in terms of changes to deflation methods that have been introduced in the U.S. after 1997, but not – or only to a very limited extent – in Europe".

The "magic" of national accounts is that they provide an instant source of detailed international comparisons, but, critics argue, on closer inspection, the numbers are not really so comparable as they are made out to be. The effect is that all sorts of easy comparisons are tossed around by policy scientists which, if the technical story behind the numbers was told, would never be attempted because the comparisons are scientifically untenable (or at the very least rather dubious).

Both the strength and the weaknesses of national accounts are that they are based on an enormous variety of data sources. The strength consists in the fact that a lot of cross-checking between data sources and data sets can occur, to assess the credibility of the estimates. The weakness is that the sheer number of inferences made from different data sets used increases the possibility of data errors, and makes it more difficult to assess error margins.

The data quality has also often been criticized on the ground that what pretends to be "data" in reality often consists only of estimates extrapolated from mathematical models, not direct observations. These models are designed to predict what particular data values ought to be, based on sample data for "indicative trends". One can, for example, observe that if variables X, Y, and Z go up, then variable P will go up as well, in a specific proportionality. In that case, one may not need to survey P or its components directly, it is sufficient to get trend data for X, Y, and Z and feed them into a mathematical model which then predicts what the values for P will be at each interval of time.

Because statistical surveys are very costly or may be difficult to organize, or because the data has to be produced rapidly to meet a deadline, statisticians often try to find cheaper, quicker, and more efficient methods to produce the data, by means of inferences from data that they already have, or from selected data which they can get more easily.

But the objection to this approach - although it can sometimes be proved to provide accurate data successfully - is that there is a loss in data accuracy and data quality.

The extrapolated estimates may lack any solid empirical basis, and the tendency is for fluctuations in the magnitudes of variables to be "smoothed out" by the estimation or interpolation procedure.

Any unexpectedly large fluctuation in a variable is difficult to predict by a mathematical model since ultimately the model's descriptions assume the future trend will conform to the law of averages and the patterns of the past.

Without adequate, comprehensive observational data from direct surveys, many of the statistical inferences made are simply not truly verifiable. All one can then say about the estimates is, that they are "probably fairly accurate, given previous and other concurrent data."

A typical reply of statisticians to this kind of objection is that although it is preferable to have comprehensive survey data available as a basis for estimation, and although data errors and inaccuracies do occur, it is possible to find techniques that keep the margins of error within acceptable bounds.

See also

Capital formation
China GDP – Dr. Fengbo Zhang introduced the Western economics, GDP, and SNA system to China, and replaced Soviet Union's MPS system.

Compensation of employees
European System of Accounts
Gross fixed capital formation
Human Development Index – an alternative way of measuring progress.

Intermediate consumption
Macroeconomics
Material Product System
Measures of national income and output
National agencies responsible for GDP measurement
National income and product accounts
Productive and unproductive labour