The macroeconomic wealth side of the WID contains the decomposition of national wealth into resident sectors (i.e., households, non-profit institutions serving households, corporations and the government) and the foreign assets and liabilitiesvis-à-visthe rest of the world.
We provide series of national wealth for most advanced economies and for a few developing countries (e.g., India, China, South Africa). The selection of countries and the time availability largely depends on the availability of official estimates of wealth aggregates, and the capacity of researchers to systematically exploit historical sources to generate long-run series of wealth.
Official balance sheets based on the SNA 2008 generally start in the 1990s. In most cases, these official series are extended backwards using a combination of historical balance sheets from official sources (i.e., based on SNA 1993 concepts and pre-SNA standards) and estimates by researchers using historical records. The general procedure followed to estimate aggregate wealth series is explained in Piketty and Zucman (2014), which produced long-run series of aggregate wealth for eight advanced economies: Australia, Canada, France, Germany, Japan, Italy, the United Kingdom and the United States. The adaptation of Piketty and Zucman’s (2014) series to the most recent national accounts system (SNA 2008) and the latest WID guidelines
has been tackled by Bauluz (2017).
Key Points
• The WID provides numerous macroeconomic series on income, wealth, popu-lation, and prices. These series are obtained by systematically combining all the existing sources under a consistent framework.
• Some key components (CFC, income from tax havens, reinvested earnings on foreign portfolio investment) have to be estimated or imputed based on limited data, at least in certain countries. These estimates are by definition more fragile and more subject to revisions than the rest.
• The data and code that was used to generate this data (at any point in time) is fully archived and freely available online athttps://github.com/
widworld/wid-world.
Income Distribution Series
This chapter deals with the reconciliation of micro and macro data in the case of income flows.
The underlying income concepts were explained in chapter 2, and chapter 6 will deal with wealth stocks. As with the previous chapter, we only explain the general principles, referring readers to methodological and country-specific papers for more details.
We assume in this chapter that we have access to comprehensive income micro files, which include annual information on individual flows of both labor and capital incomes of the entire population, and that we can use these files to compute distributional estimates that are consistent with the totals from national accounts. (See chapter 7 for situations with more limited data.) Depending on the country and the size of its informal economy, either tax or survey statistics will be dominant, while the other data set will play a supporting role. For instance, in countries with a small informal economy, and where high-quality tax microdata is available, the tax data should be used as the “main” source. In those cases, income surveys are used to make minor adjustments in order to account for non-filers and certain tax-exempt incomes. We cover this in section 5.1.
On the contrary, in most emerging countries — such as African, Asian or Latin American countries — income surveys will play the primary role, while register data is used to correct the top of the income distribution. In most of these cases, the size of the informal economy — which is not captured by administrative records by definition — is such that tax data cannot be considered as representative for the whole population, especially for middle and lower incomes.
In addition, for developed countries in earlier time periods, access to tax micro-files is not an option. Instead, less detailed income tax tabulations, which generally cover a small share of the
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adult population, are used. In section 5.2, we will discuss the methods that can be used in the case of countries and time periods where tax microdata is not the primary source.
Once the microdata is ready, the basic imputation and estimation methods that we use to produce Distributional National Accounts (DINA) series are relatively straightforward. That is, we scale fiscal income flows up to national-accounts-based income concepts and impute missing income flows in order to arrive at our benchmark concepts (i.e., pretax factor income, pretax post-replacement income, post-tax disposable income and post-tax national income as defined in chapter 2). We describe this process in sections 5.3 to 5.4. More details are provided in the country-specific papers (see in particular Piketty, Saez, and Zucman (2018) for the United States;
Garbinti, Goupille-Lebret, and Piketty (2018) and Bozio et al. (2018) for France; Bach, Bartels, and Neef (2020) for Germany; and Flores, De Rosa, and Morgan (2020) for Latin America).
5.1 Preparing Tax Microdata
In some cases researchers will have access to comprehensive administrative microdata covering a majority of the population. This is the case in a number of developed countries in recent decades.
For example, in the United States, we have access to high-quality tax micro-files covering almost the entire population since 1962 (see Piketty, Saez, and Zucman, 2018). In France, we have access to similar microfiles since 1970 (see Bozio et al., 2018; Garbinti, Goupille-Lebret, and Piketty, 2018). In Germany, we have access to triennially issued tax micro files since 1992 (see Bach, Bartels, and Neef, 2020).
But even in those countries, the income tax micro data covers only a subset of the population.
Therefore, we have to impute observations for non-filers from representative survey data.
Because the aim is to build a dataset representing the entire adult population, the imputation must take into account both the income and demographic characteristics of the adult population.
Income tax data usually reports incomes above a certain income threshold. For example, in Germany, only income tax filers above the basic annual tax allowance are included in the tax data. Thus, the individuals not reaching this income threshold should be imputed. To produce a representative dataset, we recommend using population statistics to impute observations along characteristics such as age, marital status, gender and possibly region of residence. This is important as certain population groups may not be represented equally in income tax statistics.
Typical examples are pensioners and young persons, who may be underrepresented due to small taxable incomes. Alternatively, some authors add information on the share of non-filers in the
population and their average income from survey data to the analysis.
Further blind spots in the coverage of incomes might emerge due to income specific allowances, such as an annual saver’s allowance. Capital incomes under the saver’s allowance usually do not have to be reported. Additional imputations might also be necessary for fully tax-exempt items (e.g., imputed rents of owner-occupiers, or certain tax-exempt savings accounts). Several countries have introduced a dual income tax in recent decades (Sweden in 1991, Germany in 2009, or France in 2018 among others) excluding capital incomes from the comprehensive progressive income tax and taxing them at a flat tax withheld at the source. The dual system results in missing information in tax data which must be extrapolated from former years and/or imputed from other sources such as surveys.
In some countries, employee’s tax obligations can be settled by their employer. Thus, individuals do not have to submit tax returns unless they also earn income from other sources or want to claim allowances. These incomes do not enter or only enter partially the income tax data. In the case of Croatia, Novokmet and Kump (2018) combine data from the tax withheld at source with data from individual tax returns. In the case of Germany, Bach, Bartels, and Neef (2020) impute missing employee observations from survey data. More details on imputation procedures are provided in the country-specific papers.