Imposing and Testing for Shape Restrictions in Flexible Parametric Models

In many economic models, theory restricts the shape of functions, such as monotonicity or curvature conditions. This article reviews and presents a framework for constrained estimation and inference to test for shape conditions in parametric models. We show that “regional” shape-restricting estimators have important advantages in terms of model fit and flexibility (as opposed to standard “local” or “global” shape-restricting estimators). In our empirical illustration, this is the first article to impose and test for all shape restrictions required by economic theory simultaneously in the “Berndt and Wood” data. We find that this dataset is consistent with “duality theory,” whereas previous studies have found violations of economic theory. We discuss policy consequences for key parameters, such as whether energy and capital are complements or substitutes.     

CCR or BCC: what if we are in the wrong model?

The CCR model by Charnes et al. (Eur J Oper Res 2:429–444, 1978) together with the BCC model by Banker et al. (Manag Sci 30:1078–1091, 1984) are the most popular approaches of measuring efficiency among a group of decision making units, DMUs, in data envelopment analysis, DEA. The right choice of a DEA model—CCR or BCC—often, if not always, is a difficult decision. To evaluate a DMU’s efficiency for both models might be helpful, but it does not always capture the essential issues at stake. In this paper we propose a comparative analysis of both concepts: How does activity scaling under constant BCC-efficiency influence CCR-efficiency. And inversely, how does BCC-efficiency behave when activity scaling under constant CCR-efficiency is applied. Such findings of mutual effects improve a DMU’s ability to reassess upsizing and downsizing of activities. Moreover, it allows for exact calculations of the resulting economic effects, and these effects give new insights beyond classical DEA. Finally, scale efficiency turns out to be the ideal concept to control these activity changes, rather than just CCR- or BCC-efficiency. We use a little numerical example to emphasize advantages of the new concept and sketch the new findings for a theater scenery.     

Optimization problems with color-induced budget constraints

In 1984, Gabow and Tarjan provided a very elegant and fast algorithm for the following problem: given a matroid defined on a red and blue colored ground set, determine a basis of minimum cost among those with k red elements, or decide that no such basis exists. In this paper, we investigate extensions of this problem from ordinary matroids to the more general notion of poset matroids which take precedence constraints on the ground set into account. We show that the problem on general poset matroids becomes -hard, already if the underlying partially ordered set (poset) consists of binary trees of height two. On the positive side, we present two algorithms: a pseudopolynomial one for integer polymatroids, i.e., the case where the poset consists of disjoint chains, and a polynomial algorithm for the problem to determine a minimum cost ideal of size l with k red elements, i.e., the uniform rank-l poset matroid, on series-parallel posets.     

Risk of Extreme Events in Multiobjective Decision Trees Part 1. Severe Events

Earlier work with decision trees identified nonseparability as an obstacle to minimizing the conditional expected value, a measure of the risk of extreme events, by the well-known method of averaging out and folding back. This first of two companion papers addresses the conditional expected value that is defined as the expected outcome assuming the exceedance of a threshold β, where β is preselected by the decision maker. An approach is proposed to overcome the need to evaluate all policies in order to identify the optimal policy. The approach is based on the insight that the conditional expected value is separable into two constituent elements of risk and can thus be optimized along with other objectives, including the unconditional expected value of the outcome, by using a multiobjective decision tree. An example of sequential decision making for improving highway capacity is given.     

Authors’ response: on the role of data,statistics and decisions in a pandemic

AStA Advances in Statistical Analysis -     

How is My Partner Feeling in Different Daily-Life Settings? Accuracy of Spouses' Judgements about Their Partner's Feelings at Work and at Home

How accurately do spouses know their partner's feelings when the partneris not physically present, but in a specific setting (at work, or at home)?This question addresses a special kind of empathic inference that relies mainly on content knowledge and projection rather than perception. We answered this question using a computer assisted diary approach. A total of 190 husbands and wives outof 95 couples simultaneously recorded how they were feeling and what they thought their partner was feeling, six times each day during an ordinary week. They also recorded where they were, who they were with, and where they thought their partner was. This enabled us to assess measures of accuracy and assumed similarity under natural conditions in spouses' daily lives. Results showed that the spouses' judgements of the absent partner's feelings relied on their own feelings (assumed similarity). Despite this they were often quite accurate, even when assumed similarity was controlled. In general, our findings indicate that spouses have a basic knowledge about their partner's feelings when they are apart. However, the specific situation, the items being judged, and the gender of the spouses also need to be taken into account.     

The Distribution of the German Public–Private Wage Gap

This paper provides a distributional analysis of the public–private sector wage gap in Germany from 1984 to 1996. The public sector wage distribution is generally less dispersed than the private sector wage distribution. The raw wage differential is positive for males who are at the lower tail of the male wage distribution and negative at the upper tail. In contrast, females enjoy positive wage gaps along most part of the wage distribution. A decomposition analysis reveals that the male wage premium, i.e. the part of the wage gap not accounted for by differences in observable characteristics, is uniformly negative, whereas the female wage premium is positive.