TAX POLICY AND INCOME INEQUALITY IN THE UNITED STATES, 1979–2007

This paper assesses the effects of U.S. tax policy reforms on inequality over around three decades, from 1979 to 2007. It applies a new method for decomposing changes in government redistribution into (1) a direct policy effect resulting from policy changes and (2) the effects of changing market incomes. Over the period as a whole, the tax policy changes increased income inequality by pushing up the income share of high‐income earners (the top 20%). (JEL H23, H31, H53, P16)     

Estimation in an empirical bayes model for longitudinal and cross‐sectionally clustered binary data

Some studies generate data that can be grouped into clusters in more than one way. Consider for instance a smoking prevention study in which responses on smoking status are collected over several years in a cohort of students from a number of different schools. This yields longitudinal data, also cross‐sectionaliy clustered in schools. The authors present a model for analyzing binary data of this type, combining generalized estimating equations and estimation of random effects to address the longitudinal and cross‐sectional dependence, respectively. The estimation procedure for this model is discussed, as are the results of a simulation study used to investigate the properties of its estimates. An illustration using data from a smoking prevention trial is given.     

Quantifying uncertainty in the biospheric carbon flux for England and Wales

Summary.  A crucial issue in the current global warming debate is the effect of vegetation and soils on carbon dioxide (CO₂) concentrations in the atmosphere. Vegetation can extract CO₂ through photosynthesis, but respiration, decay of soil organic matter and disturbance effects such as fire return it to the atmosphere. The balance of these processes is the net carbon flux. To estimate the biospheric carbon flux for England and Wales, we address the statistical problem of inference for the sum of multiple outputs from a complex deterministic computer code whose input parameters are uncertain. The code is a process model which simulates the carbon dynamics of vegetation and soils, including the amount of carbon that is stored as a result of photosynthesis and the amount that is returned to the atmosphere through respiration. The aggregation of outputs corresponding to multiple sites and types of vegetation in a region gives an estimate of the total carbon flux for that region over a period of time. Expert prior opinions are elicited for marginal uncertainty about the relevant input parameters and for correlations of inputs between sites. A Gaussian process model is used to build emulators of the multiple code outputs and Bayesian uncertainty analysis is then used to propagate uncertainty in the input parameters through to uncertainty on the aggregated output. Numerical results are presented for England and Wales in the year 2000. It is estimated that vegetation and soils in England and Wales constituted a net sink of 7.55 Mt C (1 Mt C = 10¹² g of carbon) in 2000, with standard deviation 0.56 Mt C resulting from the sources of uncertainty that are considered.     

Pragmatic professionalism: micro-level discourse in social work

In recent years the welfare sector has encountered numerous and often challenging changes, such as marketisation, New Public Management, and demands for evidence-based practices. These changes can be seen as a shift between the two logics of creating and maintaining authority, and as a movement from occupational towards organizational professionalism. Perhaps the most important difference between these logics is that, in occupational professionalism, authority is built on trust in the professionals’ education and ethics, whilst in organizational professionalism it is grounded in regulation and control expressed, for example, in rules, regulations, and routines. The article focuses on the ways in which two groups of social workers in Swedish social welfare offices orient themselves towards organizational and occupational professionalism in constructing themselves and in the construction of each other, as well as the work that is carried out by each group. The aim is thus to elaborate on what these logics mean at the micro-level. In this respect, pertinent questions such as ‘How are they to be understood?’, ‘Regarded from the point of view of micro politics, what do these logics mean?’ and ‘How are the logics internalized by the social workers?’ are posed.