Quantiles as optimal point forecasts

Loss functions play a central role in the theory and practice of forecasting. If the loss function is quadratic, the mean of the predictive distribution is the unique optimal point predictor. If the loss is symmetric piecewise linear, any median is an optimal point forecast. Quantiles arise as optimal point forecasts under a general class of economically relevant loss functions, which nests the asymmetric piecewise linear loss, and which we refer to as generalized piecewise linear (GPL). The level of the quantile depends on a generic asymmetry parameter which reflects the possibly distinct costs of underprediction and overprediction. Conversely, a loss function for which quantiles are optimal point forecasts is necessarily GPL. We review characterizations of this type in the work of Thomson, Saerens and Komunjer, and relate to proper scoring rules, incentive-compatible compensation schemes and quantile regression. In the empirical part of the paper, the relevance of decision theoretic guidance in the transition from a predictive distribution to a point forecast is illustrated using the Bank of England’s density forecasts of United Kingdom inflation rates, and probabilistic predictions of wind energy resources in the Pacific Northwest.     

Sample Design and Allocation for Random Digit Dialling

Sample design and sample allocation methods are developed for random digit dialling in household telephone surveys. The proposed method is based on a two-way stratification of telephone numbers. A weighted probability proportional to size sample allocation technique is used, with auxiliary variables about the telephone coverage rates, within local telephone exchanges of each substrata. This makes the sampling design nearly “self-weighting” in residential numbers when the prior information is well assigned. A computer program generates random numbers for the local areas within the existing phone capacities. A simulation study has shown greater sample allocation gain by the weighted probabilities proportional to size measures over other sample allocation methods. The amount of dialling required to obtain the sample is less than for proportional allocation. A decrease is also observed on the gain in sample allocation for some methods through the increasing sample sizes.     

A note on “Bed allocation techniques based on census data”

Capacity planning and resource allocation are crucial to the cost-effective delivery of health care services. In this paper, we present an analytic approach based on a modified version of the Holt-Winters multiplicative seasonality forecasting model to determine the frequency distribution associated with a hospital care unit's census. This paper is a follow-up to the census frequency distribution simulation model described in Lapierre et al. (Socio Econ. Plan. Sci. 33 (1999) 25). We demonstrate that our model can provide census frequency distributions equivalent to the simulation model of Lapierre et al. [1], but without the computational effort common to simulation models.     

Modelling price transmission and volatility spillover in the Slovenian wheat market

Interdependence between first and second moments of producer and consumer wheat prices in Slovenia is assessed, in light of the recent major historical events that the country has undergone, as well as the recent rumours of cartel agreements between millers causing a decline in farm-gate prices, while leaving consumer prices untouched. A threshold vector error correction and multivariate generalized autoregressive conditional heteroscedasticity model with exogenous variables is applied. Results indicate that price-level adjustments mainly favour retailers by increasing their marketing margins. Important second-moment interactions are also identified. Increases in international wheat stocks reduce producer prices, while higher interest rates increase their instability.     

Group decision-making: Head-count versus intensity of preference

This paper puts forth a framework for reshaping the group decision-making process. The proposed framework extends from the usual one-issue-at-a-time decision-making to one that involves several related issues simultaneously. Weaknesses of the traditional majority voting mechanism are first identified, and then a different voting method that takes each individual voter's sentiment into account is discussed. Specifically, a decision-maker is asked to express his/her intensity of preference for the issues encountered. Three hierarchical structures—benefits, costs, and risks—are developed to evaluate the alternatives. Due to the nature of pairwise comparisons and synthesis, the proposed method is amenable to consensus building and has higher reliability and consistency. It can be used for candidate selection, e.g. governmental election, when a large population is involved. It is also effective for resource allocation and prioritization when a small group or business is concerned. We believe the proposed approach has potential for resolving deficiencies of the conventional voting mechanism, and can be applied to many real-world problems. Its implementation on the Internet is also discussed.     

Economic development and resource degradation: Conflicts and policies

The paper develops a model that shares common features with computable general equilibrium (CGE) models. It is used to address two questions. First, what are the future prospects of a green gross domestic product (GDP); should we be concerned with resource degradation or not; and, to what extent, and under which conditions? Secondly, which policies are more effective than others? Model closures are simulated using different specifications of exogenous variables. Further, alternative policies are treated: human capital, price incentives, property rights and poverty reduction. In the African context, we show that while the prospects of environment-friendly economic development, i.e. a rising green GDP, are weak in the medium-run, under certain structural conditions there is a range of effective policies that resolves the conflict between economic growth and resource degradation, thus contributing to a rising green GDP.     

Spatial interaction modeling of interregional commodity flows

Drawing from both the spatial price equilibrium theoretical framework and the empirical literature on spatial interaction modeling, this paper expands models of interregional commodity flows (CFs) by incorporating new variables and using a flexible Box-Cox functional form. The 1993 US commodity flows survey provides the empirical basis for estimating state-to-state flow models for 16 commodity groups over the 48 continental US states. The optimized Box-Cox specification proves to be superior to the multiplicative one in all cases, while selected variables provide new insights into the determinants of state-to-state CFs.     

Transportation cost changes with statewide school district consolidation

This article studies the relationship between school district size and bus transportation costs, and estimates the change in such costs when a statewide policy of consolidation is pursued. To explore this relationship, we develop a multiple-objective model and solution procedure that combines a geographic aggregation and bus routing heuristic to generate consolidation scenarios. The heuristic was developed to explicitly consider efficiency, effectiveness, and equity objectives, and can be applied in both urban and rural states. The scenarios will generate average statewide bus transportation costs. As applied to the State of Iowa, within the legislature's proposed range of consolidation of 500-1000 students, it was found that transportation operational and capital cost increases range from 0.6 to 10.6 percent and 0.7 to 7.7 percent, respectively.     

A substitution orbit model of competitive innovations

Successful innovation and diffusion of technology can be attributed to the identification of the orbit of emerging new technologies that complement or substitute for existing technologies. This dynamism resembles the co-evolution process in an ecosystem. In an ecosystem, in order to maintain sustainable development, the complex interplay between competition and cooperation, typically observed in predator-prey systems, create a sophisticated balance. Given that an ecosystem can be used as a masterpiece system, this sophisticated balance can provide suggestive ideas for identifying an optimal orbit of competitive innovations with complement or substitution dynamism.Prompted by such a sophisticated balance in an ecosystem, this paper analyzes the optimal orbit of competitive innovations and, on the basis of an application of Lotka-Volterra equations, it reviews substitution orbits of Japan's monochrome to color TV system, fixed telephones to cellular telephones, cellular telephones to mobile Internet access service, and analog to digital TV broadcasting. On the basis of substitution orbits analyses, it attempts to extract suggestions supportive to identifying an optimal policy option in a complex orbit leading to expected orbit.Key findings include policy options that are effective in controlling parameters for Lotka-Volterra equations leading to expected orbit.