Estimating the Impact of Alternative Multiple Imputation Methods on Longitudinal Wealth Data

Statistical Analysis in surveys is often facing missing data. As case-wise deletion and single imputation prove to have undesired properties, multiple imputation remains as a measure to handle this problem. In a longitudinal study, where for some missing values past or future data points might be available, the question arises how to successfully transform this advantage into better imputation models. In a simulation study the authors compare six combinations of cross-sectional and longitudinal imputation strategies for German wealth panel data (SOEP wealth module). The authors create simulation data sets by blanking out observed data points: they induce item non response into the data by both missing at random (MAR) and two separate missing not at random (MNAR) mechanisms. We test the performance of multiple imputation using chained equations (MICE), an imputation procedure for panel data known as the row-and-columns method and a regression specification with correction for sample selection including a stochastic error term. The regression and MICE approaches serve as fallback methods when only cross-sectional data is available. Even though the regression approach omits certain stochastic components and estimators based on its result are likely to underestimate the uncertainty of the imputation procedure, it performs weak against the MICE set-up. The row-and-columns method, a univariate method, performs well considering both longitudinal and cross-sectional evaluation criteria. These results show that if the variables which ought to be imputed are assumed to exhibit high state dependency, univariate imputation techniques such as the row-and-columns imputation should not be dismissed beforehand

The relevance of inheritances and gifts in absolute and relative terms

Private wealth is a crucial factor for the economic well-being of households. Key determinants of private wealth include intergenerational wealth transfers (gifts and inheritances), which are gaining importance since 1990, as research suggests. We conduct a detailed investigation of the distribution of wealth transfers in eight Euro-area countries. First, we investigate the patterns of prevalence and level of past wealth transfers in the individual countries: Who received transfers, and what is their present value in absolute terms? We find that in most countries the percentages of households with a transfer as well as the mean present value of those transfers is increasing along the distribution of net wealth. Using a series of country-specific multivariate regressions, we find that households with higher income and education levels have both a higher probability of receiving transfers and higher absolute transfer value. We then analyze the present value of transfers as a percent of current net worth. Here, in relative terms, some of the results are reversed, as the relative importance of intergenerational transfers does not increase with the level of wealth or income. Using a fractional logit regression we conclude that for higher income quintiles the share of current net worth due to past intergenerational transfers tends to be decreasing

Reale Nettovermögen der Privathaushalte in Deutschland sind von 2003 bis 2013 geschrumpft

Studien, die die Entwicklung der Vermögen privater Haushalte in Deutschland darstellen, stützen sich typischerweise auf nominale Werte, lassen also Preissteigerungen und somit die tatsächliche Kaufkraft des Vermögens außen vor. Das DIW Berlin hat in einer aktuellen Auswertung die Inflation berücksichtigt und kommt zu dem Ergebnis: Das durchschnittliche reale Nettovermögen der Privathaushalte in Deutschland ist in den Jahren 2003 bis 2013 real um knapp 15 Prozent geschrumpft. Diese Zahl, die auf der Einkommens- und Verbrauchsstichprobe (EVS) des Statistischen Bundesamtes basiert, wird bestätigt durch Daten des Sozio-oekonomischen Panels (SOEP), denen zufolge die realen Vermögen in den Jahren 2002 bis 2012 um mehr als elf Prozent gesunken sind. Dazu beigetragen haben dürfte vor allem die schwache Entwicklung der geschätzten Marktwerte selbstgenutzter Immobilien. Dass die Volkswirtschaftlichen Gesamtrechnungen (VGR) im Kontrast zu den Ergebnissen des DIW Berlin einen Anstieg der realen Nettovermögen von 2003 bis 2013 um rund 19 Prozent ausweisen, dürfte an einer abweichenden Bewertungsmethode liegen. Für den Rückgang der realen Vermögen insgesamt dürften nicht die Top-Vermögenden verantwortlich sein: Zwar fehlen in den EVS- und SOEP-Stichproben Angaben zur Entwicklung der höchsten Vermögen, da diese in Umfragen nicht aussagekräftig repräsentiert oder gar nicht vorhanden sind. Eine Analyse der Top-Vermögenden auf Basis der Angaben des Manager Magazins legt jedoch nahe, dass deren Vermögen in den Jahren 2007 bis 2012 im Durchschnitt stagnierten. Maßgebliche Faktoren für einen erfolgreichen Vermögensaufbau sind regelmäßiges Sparen, Wertsteigerungen und vor allem Erbschaften und Schenkungen. Vermögen steigen zudem in erheblichem Umfang, wenn Schuldner regelgebunden ihre Verbindlichkeiten tilgen.Studies indicating the development of household wealth in Germany are typically based on nominal values and do not take account of price rises and thus the actual purchasing power of those assets. DIW Berlin took inflation into account in a recent evaluation and concluded that the average net worth of households in Germany decreased in real terms by almost 15 percent from 2003 to 2013. This figure, based on the German Income and Expenditure Survey (Einkommens- und Verbrauchsstichprobe, EVS) of the Federal Statistical Office, is confirmed by data from the German Socio-Economic Panel (SOEP) study and shows that real assets declined by more than 11 percent between 2002 and 2012. In particular, the weak performance of the estimated fair value of owner-occupied real estate is likely to have contributed to this decline. In contrast to DIW Berlin's findings, the national accounts system (Volkswirtschaftlichen Gesamtrechnungen, VGR) indicated an increase in real net worth of around 19 percent between 2003 and 2013. This discrepancy is likely due to the different evaluation methods used. The development of wealth held by the most affluent individuals is not likely to be responsible for the decline in the overall volume of real assets: Although the EVS and SOEP samples do not provide any details concerning the development of wealth held by the most affluent individuals, because these are either not meaningful or did not appear in the surveys at all, an analysis of the largest asset-holders based on information provided by manager magazin suggests that between 2007 and 2012 their assets stagnated on average. The relevant factors for successful wealth accumulation are regular saving, capital gains, and, in particular, inheritances and gifts. In addition, net asset values held by private households rise considerably whenever debtors pay off their liabilities in accordance with contracts

Significant statistical uncertainty over share of high net worth households

The analyses of wealth inequality based on survey data usually suffer from undercoverage of the upper percentiles of the very wealthy. Yet given this group's substantial share of total net worth, it is of particular relevance. As no tax data are available in Germany, the largest fortunes can only be simulated using "rich lists." For example, combining the Forbes list, with its approximately 50 German US dollar billionaires, with survey data results in an increased aggregate total net worth for all households in Germany in 2012 of between one-third and 50 percent, depending on the scenario. Moreover, the share of the richest one percent of the population (about 400,000 households) rises from approximately one-fifth to one-third. After reassessment, the richest ten percent of the population's share of total net worth is estimated to be between 64 and 74 percent, depending on the scenario. These reassessments are characterized by a high degree of uncertainty which eventually can only be reduced by improving the base data

Real estate price polarization projected to increase until 2030 in Germany

Demographic projections for Germany indicate a drop in the population of many regions by 2030. This is likely to have an impact on the real estate market. Our report presents the result of a model calculation of asking prices for residential real estate in Germany up to 2030 based on market data from empirica-systeme GmbH and a population projection from the Bertelsmann Foundation. Depending on the model specifications, it appears that real estate price polarization will increase by 2030. As with all model calculations, the results are subject to uncertainty. In the scenario presented here, we strictly focus on the demographic effect on real estate prices. According to our projections, in one-third of all rural districts (Landkreise) and urban districts (kreisfreie Städte), the market value of condominiums will fall by over 25 percent. This will also be the case for single- and two-family homes in one-quarter of all districts. Some regions in eastern Germany will be hit particularly hard by this development. In and around urban centers, however, the trend of rising prices is expected to continue. Our findings also show that the polarization of real estate prices might cause the inequality of wealth in Germany to rise slightly

Persistently high wealth inequality in Germany

According to current analyses based on the Socio-Economic Panel Study (SOEP), the total net assets of German households in 2012 amounted to 6.3 trillion euros. Almost 28 percent of the adult population had no or even negative net wealth. On average, individual net assets in 2012 totaled over 83,000 euros, slightly more than ten years previously. The degree of wealth inequality also remained virtually unchanged. With a Gini coefficient of 0.78, Germany has a high degree of wealth inequality compared to other countries, and there is still a wide gap between western and eastern Germany almost 25 years after unification. In 2012, the average net wealth of eastern Germans was less than half that of western Germans

Zunehmende Polarisierung der Immobilienpreise in Deutschland bis 2030

Die demografische Entwicklung in Deutschland bis zum Jahr 2030 wird in vielen Regionen zu einer rückläufigen Bevölkerungszahl führen. Dies dürfte auch Auswirkungen auf den Immobilienmarkt haben. Dieser Bericht präsentiert Ergebnisse einer Modellrechnung der Angebotspreise für Wohnimmobilien in Deutschland bis zum Jahr 2030, basierend auf den empirica-systeme-Marktdaten und einer Bevölkerungsvorausberechnung der Bertelsmann-Stiftung. Je nach Modellspezifikation zeigt sich eine zunehmende Polarisierung der Immobilienpreise bis zum Jahre 2030. Wie bei allen Modellrechnungen sind die Ergebnisse mit Unsicherheit behaftet, nicht zuletzt, weil auf die Immobilienpreise viele verschiedene Faktoren einwirken. Im hier präsentierten Szenario liegt der Fokus allein auf dem demografischen Effekt auf die Immobilienpreise. Danach werden in einem Drittel aller Kreise und kreisfreien Städten die Marktwerte von Eigentumswohnungen um mehr als 25 Prozent sinken, bei Ein- und Zweifamilienhäusern dürfte dies bei einem Viertel der Kreise der Fall sein. Vor allem Regionen in Ostdeutschland werden von dieser Entwicklung betroffen sein. Demgegenüber ist in und um Ballungszentren mit weiteren Preisanstiegen zu rechnen. Die Ergebnisse zeigen auch, dass mit der Polarisierung der Immobilienpreise die Vermögensungleichheit in Deutschland leicht zunehmen könnte

Real met worth of households in Germany fell between 2003 and 2013

Studies indicating the development of household wealth in Germany are typically based on nominal values and do not take account of price rises and thus the actual purchasing power of those assets. DIW Berlin took inflation into account in a recent evaluation and concluded that the average net worth of households in Germany decreased in real terms by almost 15 percent from 2003 to 2013. This figure, based on the German Income and Expenditure Survey (Einkommens- und Verbrauchsstichprobe, EVS) of the Federal Statistical Office, is confirmed by data from the German Socio- Economic Panel (SOEP) study and shows that real assets declined by more than 11 percent between 2002 and 2012. In particular, the weak performance of the estimated fair value of owner-occupied real estate is likely to have contributed to this decline. In contrast to DIW Berlin's findings, the national accounts system (Volkswirtschaftlichen Gesamtrechnungen, VGR) indicated an increase in real net worth of around 19 percent between 2003 and 2013. This discrepancy is likely due to the different valuation methods used. The development of wealth held by the most affluent individuals is not likely to be responsible for the decline in the overall volume of real assets: Although the EVS and SOEP samples do not provide any details concerning the development of wealth held by the most affluent individuals, because these are either not meaningful or did not appear in the surveys at all, an analysis of the fortunes asset-holders based on information provided by manager magazin suggests that between 2007 and 2012 their assets stagnated on average. The relevant factors for successful wealth accumulation are regular saving, capital gains, and, in particular, inheritances and gifts. In addition, net asset values held by private households rise considerably whenever debtors pay off their liabilities in accordance with contracts