Item Non-response and Imputation of Annual Labor Income in Panel Surveys from a Cross-National Perspective

Using data on annual individual labor income from three representative panel datasets (German SOEP, British BHPS, Australian HILDA) we investigate a) the selectivity of item non-response (INR) and b) the impact of imputation as a prominent post-survey means to cope with this type of measurement error on prototypical analyses (earnings inequality, mobility and wage regressions) in a cross-national setting. Given the considerable variation of INR across surveys as well as the varying degree of selectivity build into the missing process, there is substantive and methodological interest in an improved harmonization of (income) data production as well as of imputation strategies across surveys. All three panels make use of longitudinal information in their respective imputation procedures, however, there are marked differences in the implementation. Firstly, although the probability of INR is quantitatively similar across countries, our empirical investigation identifies cross-country differences with respect to the factors driving INR: survey-related aspects as well as indicators accounting for variability and complexity of labor income composition appear to be relevant. Secondly, longitudinal analyses yield a positive correlation of INR on labor income data over time and provide evidence of INR being a pre-dictor of subsequent unit-non-response, thus supporting the "cooperation continuum" hy-pothesis in all three panels. Thirdly, applying various mobility indicators there is a robust picture about earnings mobility being significantly understated using information from completely observed cases only. Finally, regression results for wage equations based on observed ("complete case analysis") vs. all cases and controlling for imputation status, indicate that individuals with imputed incomes, ceteris paribus, earn significantly above average in SOEP and HILDA, while this relationship is negative using BHPS data. However, once applying the very same imputation procedure used for HILDA and SOEP, namely the "row-and-column-imputation" approach suggested by Little & Su (1989), also to BHPS-data, this result is reversed, i.e., individuals in the BHPS whose income has been imputed earn above average as well. In our view, the reduction in cross-national variation resulting from sensitivity to the choice of imputation approaches underscores the importance of investing more in the improved cross-national harmonization of imputation techniques.Item non-response, imputation, income inequality, income mobility, panel data, SOEP, BHPS, HILDA

Item Non-response and Imputation of Annual Labor Income in Panel Surveys from a Cross-National Perspective

Using data on annual individual labor income from three representative panel datasets (German SOEP, British BHPS, Australian HILDA) we investigate a) the selectivity of item non-response (INR) and b) the impact of imputation as a prominent post-survey means to cope with this type of measurement error on prototypical analyses (earnings inequality, mobility and wage regressions) in a cross-national setting. Given the considerable variation of INR across surveys as well as the varying degree of selectivity build into the missing process, there is substantive and methodological interest in an improved harmonization of (income) data production as well as of imputation strategies across surveys. All three panels make use of longitudinal information in their respective imputation procedures, however, there are marked differences in the implementation. Firstly, although the probability of INR is quantitatively similar across countries, our empirical investigation identifies cross-country differences with respect to the factors driving INR: survey-related aspects as well as indicators accounting for variability and complexity of labor income composition appear to be relevant. Secondly, longitudinal analyses yield a positive correlation of INR on labor income data over time and provide evidence of INR being a predictor of subsequent unit-non-response, thus supporting the "cooperation continuum" hypothesis in all three panels. Thirdly, applying various mobility indicators there is a robust picture about earnings mobility being significantly understated using information from completely observed cases only. Finally, regression results for wage equations based on observed ("complete case analysis") vs. all cases and controlling for imputation status, indicate that individuals with imputed incomes, ceteris paribus, earn significantly above average in SOEP and HILDA, while this relationship is negative using BHPS data. However, once applying the very same imputation procedure used for HILDA and SOEP, namely the "row-and-columnimputation" approach suggested by Little & Su (1989), also to BHPS-data, this result is reversed, i.e., individuals in the BHPS whose income has been imputed earn above average as well. In our view, the reduction in crossnational variation resulting from sensitivity to the choice of imputation approaches underscores the importance of investing more in the improved cross-national harmonization of imputation techniques.Item non-response, imputation, income inequality, income mobility, panel data, SOEP, BHPS, HILDA

Old-Age Pension Entitlements Mitigate Inequality: But Concentration of Wealth Remains High

Entitlements from old-age pension schemes - statutory, company, and private - represent a considerable source of wealth. For data-related reasons, analyses of the personal wealth distribution have so far failed to take this into account, however. According to recent calculations based on the 2007 data of the German Socio- Economic Panel (SOEP), the present value of total pension and state annuity entitlements (not including entitlements to provision for dependants) amounted to roughly 4.6 trillion euros. This corresponds to an average of 67,000 euros per adult. When this is combined with individuals' financial and material assets, which amount to an average of 88,000 euros, the result is a more comprehensive total net worth of more than 155,000 euros. Civil servants and retired civil servants fare better than average if this larger view is taken. This more comprehensive measurement shows considerably less inequality of wealth than traditional analyses, which refer only to financial and material assets. This is not least because of the very widespread existence of entitlements under the various old-age pension schemes with simultaneous capping based on the contribution assessment threshold for statutory pension schemes. Nevertheless, wealth continues to be highly concentrated, and the mitigating effects of old-age pension assets will likely become less important in the future. Here the effects of falling pension levels as a result of reforms in the old-age pension systems and growing gaps in earnings histories will be felt - with the risk of increasing poverty among the future elderly.Wealth inequality, Pension entitlements, SOEP

Missing Income Data in the German SOEP: Incidence, Imputation and its Impact on the Income Distribution

This paper deals with the question of selectivity of missing data on income questions in large panel surveys due to item-non-response and with imputation as one alternative strategy to cope with this issue. In contrast to cross-section surveys, the imputation of missing values in panel data can profit from longitudinal information which is available for the very same observation units from other points in time. The "row-and-column imputation procedure" developed by Little & Su (1989) considers longitudinal as well as cross-sectional information in the imputation process. This procedure is applied to the German Socio-Economic Panel study (SOEP) when deriving annual income variables, complemented by purely cross-sectional techniques. Based on the SOEP, our empirical work starts with a description of the overall incidence of imputation and its relevance given by imputed income as a percentage share of the total income mass: e.g. while 21 % of all observations have at least one missing income component of their pre-tax post-transfer income, 9 % of the overall income mass is imputed. However, this picture varies considerably for more recent sub-samples of the panel survey. Secondly, we analyze the respective impact of imputation on the personal distribution of income as well as on results of income mobility. When comparing income inequality measures based only on truly observed information to those derived from all (i.e., observed and imputed) observations, we find an increase in inequality due to imputation and this effect appears to be relevant in both tails of the distribution, although somewhat more prominent among higher incomes. Longitudinal analyses show firstly a positive correlation of item-non-response on income data over time, but also provide evidence of item-non-response as being a predictor of subsequent unit-non-response. Applying various income mobility indicators there is a robust picture about income mobility being understated using truly observed information only. Finally, multivariate models show that survey-related factors (number of interviews, interview mode) as well as indicators for variability in income receipt (due to increased complexity of household structure and income composition) are significantly correlated with item-non-response. In conclusion, our empirical results based on the German SOEP indicate the selectivity of item-non-response on income questions in social surveys and push the necessity for adequate imputation.Item-Non-Response, Imputation, Income Inequality

CAN THE UNITED STATES COMPETE WITH DAIRY EXPORTING NATIONS?

International Relations/Trade,

The Personal Distribution of Income and Imputed Rent: A Cross-National Comparison for the UK, West Germany and the USA

This article deals with income advantages derived from owner occupied housing (Imputed Rent, IR) and their impact on the personal income distribution. Following a brief description of different methods with which to calculate IR in household surveys, we conduct a cross-national comparative study based on micro-data from the British Household Panel Study (BHPS), the German Socio- Economic Panel (SOEP), and the US Panel Study of Income Dynamics (PSID). We find distinct differences between the Anglo-Saxon countries and Germany in terms of prevalence and extent of IR as well as in terms of the impact on the overall income distribution. In all three countries, however, using IR in measures of old age provision improves the quality of economic well-being assessment for the elderly.Personal Income Distribution, Owner Occupied Housing, Imputed Rent, Old Age Provision

Accounting for Imputed and Capital Income Flows in Income Inequality Analyses

Using representative and consistent microdata from the German Socio-Economic Panel Study (SOEP) from 1985-2007, we illustrate that capital income (CI = return on financial investments) and imputed rent (IR = return on investments in owner-occupied housing) have become increasingly important sources of economic inequality in Germany over the last two decades. Whereas the operationalization of CI in this paper is based on monetary returns on financial investments only, our definition of IR follows a regulation by the European Commission, (EC) which is currently being used to harmonize income measurement for the European Statistics on Income and Living Conditions (EU-SILC) in Europe. While both of these components represent some kind of return on alternative private investments, our results indicate that they do not coincide in their impacts on income inequality and poverty. In line with the literature, net IR as defined according to the EC regulation tends to exert a dampening effect on inequality and relative poverty, very much driven by the increasing share of outright ownership among the elderly. On the other hand, inequality is boosted by CI especially when looking at the upper tail of the income distribution. As the German public pension scheme gradually loses its ability to maintain people's living standards into retirement, we find these effects to increase over time. The analyses presented here, exemplified for Germany, make a clear case for the joint consideration of all components of private investment income for the purpose of welfare analysis, be they of a monetary or non-monetary nature. This appears to be relevant in at least three dimensions of comparative research: (1) across time; (2) across space, regions, welfare regimes; (3) across the individual life course, thus analyzing the impact of investment income on intrapersonal mobility patterns.income inequality, decomposition, capital income, imputed rent, SOEP

Lifetime of Surface Features and Stellar Rotation: A Wavelet Time-Frequency Approach

We explore subtle variations in disk-integrated measurements spanning \lsim 18 years of stellar surface magnetism by using a newly developed time-frequency gapped wavelet algorithm. We present results based on analysis of the Mount Wilson Ca II H and K emission fluxes in four, magnetically-active stars (HD 1835 [G2V], 82885 [G8IV-V], 149661 [K0V] and 190007 [K4V]) and sensitivity tests using artificial data. When the wavelet basis is appropriately modified (i.e., when the time-frequency resolution is optimized), the results are consistent with the existence of spatially localized and long-lived Ca II features (assumed here as activity regions that tend to recur in narrowly-confined latitude bands), especially in HD 1835 and 82885. This interpretation is based on the observed persistence of relatively localized Ca II wavelet power at a narrow range of rotational time scales, enduring as long as \gsim 10 years.Comment: to appear in THE ASTROPHYSICAL JOURNAL LETTER

Wealth Inequality on the Rise in Germany

Individual net wealth in Germany totaled an average of around 88,000 Euros at the beginning of 2007 which was about 10 percent higher than in 2002. Decisive for this development was an increase in monetary wealth as well as wealth from private insurance. In connection with the overall quite unequal division of wealth, the median i.e., the value which separates the richest 50 per cent of the population from the poorest, continues to be only around 15,000 Euros. Nonetheless, around two thirds of the population of 17 years of age and above did not possess any or very little monetary and material wealth. So, on the whole, wealth inequality in Germany has continued to increase since 2002. Within the scope of this development, the wealth inequalities which already existed between West and East Germany have further increased since 2002, which has primarily been as a result of the decreasing market value of property in East Germany. Reforms of the state system providing for old age demand a reinforcement of private and company pension plans. Here, private asset accumulation through investment in owner-occupied properties and regular savings activity-also government sponsored-has particular significance in the maintenance of living standards after retirement.Wealth Inequality, Mobility, Composition, SOEP