Estimates of semiparametric equivalence scales

Within the semiparametric framework introduced by Pendakur ( 1999 ) we introduce a new loss function to estimate equivalence scales. This loss function uses all available information from the total expenditures of both the reference and nonreference households and as such it produces more reliable estimates. Using Canadian family expenditure data for 1996 we apply this loss function to obtain equivalence scale estimates for a variety of expenditure share categories such as food, fuel and clothing. Copyright © 2006 John Wiley & Sons, Ltd.     

The long and short of asking questions about income: a comparison using data from Hungary

A lot of research on income mobility and income inequality is based on survey questions about income. Various question formats are being used. Researchers seem to assume that the actual format used delivers the best estimate of the “true” income. However, surprisingly little empirical support is available for this claim. We implemented an experimental design using the short and long versions of income questions in a Hungarian survey. Results show an overall positive difference between the long and short version. The differences are related to the income components (wages and salaries, transfers, and assets), and respondent characteristics, controlling for the effect of the order of the two versions of income questions. Based on the results, we provide some recommendations for implementing income questions in surveys.     

Direct Estimation of Equivalence Scales and More Evidence on Independence of Base

We explore a direct approach to estimating household equivalence scales from income satisfaction data. Our method differs from previous approaches to using satisfaction data for this purpose in that it can be used to directly fit and evaluate closed‐form and non‐parametric equivalence scales of any desired form. Its flexibility makes it easy to consider specific aspects such as income dependence or more specific information on household composition (such as whether household members live in a partner relationship). We estimate and evaluate a number of scales used in the literature. If the equivalence scale is assumed to be independent of income and to depend only on household size, we do not reject the validity of the widely used square‐root scale at conventional significance levels. We also test GESE and GAESE restrictions (Donaldson and Pendakur, 2003, 2006) and investigate in detail to what extent household economies of scale depend on income. Our results suggest that the income dependence differs fundamentally across household types (rising economies of scale for ‘family’ households, falling economies of scale for multi‐adult households without children and no income dependence for other households).     

Testing the capital asset pricing model efficiently under elliptical symmetry: a semiparametric approach

We develop new tests of the capital asset pricing model that take account of and are valid under the assumption that the distribution generating returns is elliptically symmetric; this assumption is necessary and sufficient for the validity of the CAPM. Our test is based on semiparametric efficient estimation procedures for a seemingly unrelated regression model where the multivariate error density is elliptically symmetric, but otherwise unrestricted. The elliptical symmetry assumption allows us to avoid the curse of dimensionality problem that typically arises in multivariate semiparametric estimation procedures, because the multivariate elliptically symmetric density function can be written as a function of a scalar transformation of the observed multivariate data. The elliptically symmetric family includes a number of thick‐tailed distributions and so is potentially relevant in financial applications. Our estimated betas are lower than the OLS estimates, and our parameter estimates are much less consistent with the CAPM restrictions than the corresponding OLS estimates. Copyright © 2002 John Wiley & Sons, Ltd.     

Smoothed binary regression quantiles

This paper extends results regarding smoothed median binary regression to general smoothed binary quantile regression, discusses the interpretation of the resulting estimators under alternative assumptions, and shows how they may be used to obtain semiparametric estimates of counterfactual probabilities. The estimators are applied to a model of labour force participation of married women in the USA. We find that the elasticity with respect to non‐labour income is significantly negative only for women that belong to the middle of the conditional willingness‐to‐participate (WTP) distribution. In comparing the quantile models with parametric logit and semiparametric single‐index specifications, we find that the models agree closely for women around the centre of the WTP distribution, but there are considerable disagreements as we move towards the tails of the distribution. Copyright © 2006 John Wiley & Sons, Ltd.     

Income distribution and well‐being: what can we learn from subjective data?

Abstract. How does the income of others affect my own welfare? This survey of the empirical literature stresses the contribution of subjective data to the understanding of this issue, with an attempt to disentangle direct effects (preference interdependence) from indirect informational effects. It shows that perceived mobility is central to the link between other people's income and individual satisfaction, as it determines individual opportunities and risks. Agents also appreciate the egalitarian nature of mobility itself, so that individual welfare depends on dynamic inequality rather than static income distribution. These studies illustrate how subjective data can bring information on aspects of utility and social interactions that are beyond the scope of the method based on action‐revealed preferences.     

Semiparametric econometrics: A survey

Semiparametric econometric models contain both parametric and nonparametric components, reflecting in some fashion what has been learned from economic theory and previous empirical experience, and what remains unknown. They raise such questions as how well the parametric component can be estimated, and how to construct rules of inference with good statistical properties. The paper attempts to survey the econometric and most relevant statistical literature on semiparametric inference, and includes a partial bibliography.     

Pay for (individual) performance: Issues,claims, evidence and the role of sorting effects

We address two broad questions: how much pay for individual performance (PFIP) is there and what are the positive and negative effects of PFIP? We consider specific claims, including that PFIP does not motivate (or even de-motivates), that it is ineffective in teams, and that it is ineffective in some national cultures. We demonstrate how incorporating sorting effects of PFIP into conceptual treatments of PFIP can change how one views the likely effectiveness of PFIP across contexts.     

Judgmental aggregation strategies depend on whether the self is involved

We report the results of a novel experiment that addresses two unresolved questions in the judgmental forecasting literature. First, how does combining the estimates of others differ from revising one’s own estimate based on the judgment of another? The experiment found that participants often ignored advice when revising an estimate but averaged estimates when combining. This was true despite receiving identical feedback about the accuracy of past judgments. Second, why do people consistently tend to overweight their own opinions at the expense of profitable advice? We compared two prominent explanations for this, differential access to reasons and egocentric beliefs, and found that neither adequately accounts for the overweighting of the self. Finally, echoing past research, we find that averaging opinions is often advantageous, but that choosing a single judge can perform well in certain predictable situations.     

Cut Child Benefits to Cut Taxes

Should the well-off benefit from fiscal resources if they choose to have children? Professor Michael Beenstock of the City University Business School argues that they should not. Child Benefit, in common with other fiscal subventions, should be limited to families in most need. Dr lvy Papps in the last issue argued the case for selectivity in Child Benefit. Professor Beenstock's proposal represents a radical departure from the present arrangements under which Child Benefit is universal, regardless of family income, and he calculates the cuts in income tax that could follow. Given the size of his family (above). Professor Beenstock is obviously more interested in economic truth than personal advantage.     

If You Are So Smart,Why Aren't You an Entrepreneur? Returns to Cognitive and Social Ability: Entrepreneurs Versus Employees

How valuable are cognitive and social abilities for entrepreneurs’ relative to employees’ earnings? We answer three questions: (1) To what extent does a composite measure of ability affect an entrepreneur's earnings relative to wages earned by employees? (2) Do different cognitive abilities (e.g., math ability, language, or verbal ability) and social ability affect earnings of entrepreneurs and employees differently?, and (3) Does the balance in these measured ability levels affect an individual's earnings? Our (difference‐of‐difference) estimates of the returns to ability for spells in entrepreneurship versus wage employment account for selectivity into entrepreneurial positions insofar as they are determined by fixed individual characteristics. Our robust results provide the following answers to the three questions: General ability has a stronger impact on entrepreneurial incomes than on wages. Moreover, entrepreneurs and employees benefit from different sets of specific abilities: verbal and clerical abilities have a stronger impact on wages, whereas mathematical, social, and technical ability are more valuable for entrepreneurs. The balance in the various kinds of ability also generates a higher income, but only for entrepreneurs: This finding supports Lazear's Jack‐of‐all‐Trades theory.     

Local multiplicative bias correction for asymmetric kernel density estimators

We consider semiparametric asymmetric kernel density estimators when the unknown density has support on [0,∞)$[0,\infty )$. We provide a unifying framework which relies on a local multiplicative bias correction, and contains asymmetric kernel versions of several semiparametric density estimators considered previously in the literature. This framework allows us to use popular parametric models in a nonparametric fashion and yields estimators which are robust to misspecification. We further develop a specification test to determine if a density belongs to a particular parametric family. The proposed estimators outperform rival non- and semiparametric estimators in finite samples and are easy to implement. We provide applications to loss data from a large Swiss health insurer and Brazilian income data.     

Optimally combining censored and uncensored datasets

We develop a simple semiparametric framework for combining censored and uncensored samples so that the resulting estimators are consistent, asymptotically normal, and use all information optimally. No nonparametric smoothing is required to implement our estimators. To illustrate our results in an empirical setting, we show how to estimate the effect of changes in compulsory schooling laws on age at first marriage, a variable that is censored for younger individuals. Results from a small simulation experiment suggest that the estimator proposed in this paper can work very well in finite samples.     

Time costs,aspirations and the effect of economic growth on German fertility

Recent research has shown strong support for the model of reproductive behavior derived from the new home economics, and it is shown in this discussion that the evidence from the Federal Republic of Germany is consistent with the new home economics model. There is little support for Easterlin's relative economic hypothesis, but there is limited endorsement for model which adds the influence of experience based material aspirations to the new home economics model. Easterlin's relative income model is reviewed before directing attention to the new home economics model and an explanation of fertility movements in West Germany. The new home economics model focuses on the family division of labor between home activities and work outside the home. The marked decline in German fertility during the 1970s is mostly attributable to factors such as expanding women's earning capacities which increased the importance of 2 earner families, who have a different family division of labor and possibly preferences biased towards "quality" of children rather than numbers. Also, real wage growth lagged behind the growth in experience based aspirations, and this drop in relative income is more dramatic if it is presumed that material aspirations are based upon the family's income experienced by a young adult during his/her adolescence, rather than just the father's earnings. The mother's contribution to family income will contribute to her family's actual standard of living and the desired standard of living of her children. The labor force participation rates of married, middle-aged German women increased markedly during the 1st half of the 1950s, thus tending to enhance the increase in the standard of living desired by the young adults reaching marrying and childbearing ages in the mid-1960s. The analysis indicates that if there is not a substantial reduction in the proportion of young married women in the labor force, fertility will move countercyclically. In that there must be some floor to fertility, one should be cautious of using these parameter estimates considerably outside the 1950-1977 period. Nonetheless, the estimates indicate that economic growth will not bring a substantial rise in German fertility, and, outside the unlikely situation of sustained economic decline, fertility will remain low.     

Life-cycle variations in the association between current and lifetime earnings: Evidence for German natives and guest workers

In many economic models a central variable of interest is lifetime or permanent income which is not observed in survey data sets and typically proxied by annual income information. To assess the quality of such approximations, we use a unique source of lifetime earnings — the German pension system — and focus on two important issues that have been largely ignored in the existing literature. The first is how to deal with zero income observations in the analysis of women. The second is whether these approximations differ between natives and guest workers. For female earners, we find that estimates of the associations between current and lifetime income are highly sensitive to the treatment of zero earnings. The reason turns out to be the highly cyclical nature of the labor supply behavior of mothers. Furthermore, immigrants' income proxies are prone to significantly larger attenuation biases over the entire life-cycle. This result is explained by the larger share of annual income variance attributable to the transitory income component for immigrants. Averaging income over up to 15 years alleviates the attenuation bias as well as the difference in biases between natives and guest workers.     

Pseudo-maximum likelihood estimation in two classes of semiparametric diffusion models

Two classes of semiparametric diffusion models are considered, where either the drift or the diffusion term is parameterized, while the other term is left unspecified. We propose a pseudo-maximum likelihood estimator (PMLE) of the parametric component that maximizes the likelihood with a preliminary estimator of the unspecified term plugged in. It is demonstrated how models and estimators can be used in a two-step specification testing strategy of semiparametric and fully parametric models, and shown that approximate/simulated versions of the PMLE inherit the properties of the actual but infeasible estimator. A simulation study investigates the finite sample performance of the PMLE.     

Do Off‐Label Drug Practices Argue Against FDA Efficacy Requirements? A Critical Analysis of Physicians' Argumentation for Initial Efficacy Requirements

The amended Food, Drug and Cosmetics Act requires efficacy certification for a drug's initial uses (“on‐label”), but does not require certification before physicians may prescribe the drug for subsequent uses (“off‐label”). Does it make sense to require FDA efficacy certification for new drugs but not for new uses of old drugs? Using a sequential online survey, we carried on a “virtual conversation” with some 500 physicians. The survey asked whether efficacy requirements should be imposed on off‐label uses; almost all physicians said no. It asked whether the efficacy requirements for initial uses should be dropped, and most physicians said no. We then asked respondents whether opposing efficacy requirements in one case but not the other involved an inconsistency. In response, we received hundreds of written commentaries. We organize and discuss these commentaries with an eye to understanding how the medical market certifies off‐label drug uses and how this compares to FDA certification. Does off‐label medicine use suggest that efficacy requirements should be placed on new uses of old drugs? Does it suggest that efficacy requirements on new drugs should be lifted? We explore these questions, and ask whether the response of many of the doctors exhibits the familiar behavior bias toward the status quo.     

Designing software for operational decision support through coloured Petri nets

Operational support provides, during the execution of a business process, replies to questions such as ‘how do I end the execution of the process in the cheapest way?’ and ‘is my execution compliant with some expected behaviour?’ These questions may be asked several times during a single execution and, to answer them, dedicated software components (the so-called operational support providers) need to be invoked. Therefore, an infrastructure is needed to handle multiple providers, maintain data between queries about the same execution and discard information when it is no longer needed. In this paper, we use coloured Petri nets (CPNs) to model and analyse software implementing such an infrastructure. This analysis is needed to clarify the requirements before implementation and to guarantee that the resulting software is correct. To this aim, we present techniques to represent and analyse state spaces with 250 million states on a normal PC. We show how the specified requirements have been implemented as a plug-in of the process mining tool ProM and how the operational support in ProM can be used in combination with an existing operational support provider.