Minimax Rates for Estimating the Variance and its Derivatives in Non–Parametric Regression

In this paper the van Trees inequality is applied to obtain lower bounds for the quadratic risk of estimators for the variance function and its derivatives in non–parametric regression models. This approach yields a much simpler proof compared to previously applied methods for minimax rates. Furthermore, the informative properties of the van Trees inequality reveal why the optimal rates for estimating the variance are not affected by the smoothness of the signal g . A Fourier series estimator is constructed which achieves the optimal rates. Finally, a second–order correction is derived which suggests that the initial estimator of g must be undersmoothed for the estimation of the variance.     

On 'class exploitation' in Canada†

Two things make Carl Cuneo's recent (1978) paper on 'rates of exploitation' in Canada remarkable. The first is the magnitudes involved. Cuneo's preferred measure of surplus value (RSV₇), for instance, shows a more than seven-fold increase from 1917 to 1971, indicating a quite spectacular shift in favour of capital in relative income shares in Canadian manufacturing industry. The second thing that makes Cuneo's paper remarkable is the extent to which his findings are inconsistent with findings on income shares reported by 'bourgeois' economists. In a survey of the literature Pen (1971: 164 ff.), for example, reports that in the advanced capitalist economies, the share of income accruing to labour in the economy as a whole has increased substantially and that even if one confines one's attention to the private sector the share of manual workers has not decreased but remained more or less constant in spite of the relative decline in their numbers.¹ Now, it is true that the studies reviewed by Pen approach the problem of income shares with the categories of 'bourgeois' economics while Cuneo approaches the problem with what he regards as Marxist categories, and it is conceivable that this might have accounted for the radical difference in the findings. But still, differences of such magnitude in the trends reported in the shares of capital and labour both give pause and urge a close scrutiny.     

Approaches to Stimulating Change in Mature Insurance Companies

The findings reported in this paper address problems confronting chief executives and functional specialists involved in turnaround situations. A comparison is undertaken of companies in which innovation was successfully started – called 'pacesetters'– with companies which were less successful. Starting innovation was an important precursor for profitability in all the companies studied. Without change there would be no tomorrow. In pacesetter companies, chief executives used an unconventional approach to shock staff into action. They ruthlessly opened minds to market threats and opportunities. After administering shock treatment, they carefully returned responsibility to first line managers through a deliberate 'managerial shift'. They insisted that the new style of managing they introduced be market-focused. In contrast, chief executives of companies which were less successful at starting innovation encouraged debate on alternative strategies as a prelude to any action. This apparently more logical approach led to frequent disagreements which sapped employee motivation. It lacked the urgency of an approach firmly grounded in the realities of the market place.     

Nonparametric validation of similar distributions and assessment of goodness of fit

In this paper the problem of assessing the similarity of two cumulative distribution functions F and G is considered. An asymptotic test based on an α-trimmed version of Mallows distance Γ_α( F , G ) between F and G is suggested, thus demonstrating the similarity of F and G within a preassigned Γ_α( F , G ) neighbourhood at a controlled type I error rate. The test proposed is applied to the validation of goodness of fit and for the nonparametric assessment of bioequivalence. It is shown that Γ_α( F , G ) can be interpreted as average and population equivalence. Our approach is illustrated by various examples.     

An omnibus CUSUM chart for monitoring time to event data

A non-parametric method is proposed for monitoring time-to-event data. A cumulative sum chart is constructed that is able to detect an unknown out-of-control state. This method exploits the absolute differences between the Kaplan–Meier estimator and the in-control distribution over specific time intervals. The efficiency of the algorithm is studied via a simulation and a real data study. The new method is also tested via the simulation study against existing methods.     

Calling social capital: An analysis of the determinants of success on the TV quiz show “Who Wants to Be a Millionaire?”

This paper analyzes the determinants of successful participation of candidates on the well known television quiz show “Who Wants to Be a Millionaire?”. Our study includes a survey of 660 contestants who participated in the German version of the show between 1999 and 2007. We are particularly interested in two hypotheses. The first hypothesis refers to the assumed advantage of social capital. Contestants on the show have the option of calling a friend (the phone-a-friend lifeline) whom they select from their personal networks. The person chosen to be the phone-a-friend lifeline should be especially helpful if the contestant has a large network of able contacts from which to choose. Second, according to human capital theory the participants’ education should increase the chances of success and should lead on average to higher payoffs. Since contestants on the show can answer questions correctly mainly on the basis of their knowledge and since other characteristics of the candidates are irrelevant, estimates of the human capital effect are not affected by other possible causes suggested by signaling theory. Thus, our analysis is an assessment of the effects of social capital and human capital on the show.     

Valuing mortality risk reductions from environmental, transport, and health policies: a global meta-analysis of stated preference studies

We conduct, to our knowledge, the first global meta-analysis (MA) of stated preference (SP) surveys of mortality risk valuation. The surveys ask adults their willingness to pay (WTP) for small reductions in mortality risks, deriving estimates of the sample mean value of statistical life (VSL) for environmental, health, and transport policies. We explain the variation in VSL estimates by differences in the characteristics of the SP methodologies applied, the population affected, and the characteristics of the mortality risks valued, including the magnitude of the risk change. The mean (median) VSL in our full data set of VSL sample means was found to be around $7.4 million (2.4 million) (2005 U.S. dollars). The most important variables explaining the variation in VSL are gross domestic product (GDP) per capita and the magnitude of the risk change valued. According to theory, however, VSL should be independent of the risk change. We discuss and test a range of quality screening criteria in order to investigate the effect of limiting the MA to high-quality studies. When limiting the MA to studies that find statistically significant differences in WTP using external or internal scope tests (without requiring strict proportionality), we find that mean VSL from studies that pass both tests tend to be less sensitive to the magnitude of the risk change. Mean VSL also tends to decrease when stricter screening criteria are applied. For many of our screened models, we find a VSL income elasticity of 0.7-0.9, which is reduced to 0.3-0.4 for some subsets of the data that satisfy scope tests or use the same high-quality survey.     

Impulse Balance and Multiple‐Period Feedback in the Newsvendor Game

Human subjects in the newsvendor game place suboptimal orders: orders are typically between the expected profit‐maximizing quantity and mean demand (“pull‐to‐center bias”). In previous work, we have shown that impulse balance equilibrium (IBE), which is based on a simple ex post rationality principle along with an equilibrium condition, can predict ordering decisions in the laboratory. In this study, we extend IBE to standing orders and multiple‐period feedback and show that it predicts—in line with previous findings—that constraining newsvendors to make a standing order for a sequence of periods moves the average of submitted orders toward the optimum.