Optimum allocation in multivariate stratified random sampling: stochastic matrix mathematical programming

The allocation problem for multivariate stratified random sampling as a problem of stochastic matrix integer mathematical programming is considered, minimizing the estimated covariance matrix of estimated means subject to fixed cost or fixed total sample size. With these aims the asymptotic normality of sample covariance matrices for each strata is established. Some alternative approaches are suggested for its solution. An example is solved by applying the proposed techniques.     

The structure of strategy-proof random social choice functions over product domains and lexicographically separable preferences

We characterize the class of dominant-strategy incentive-compatible (or strategy-proof) random social choice functions in the standard multi-dimensional voting model where voter preferences over the various dimensions (or components) are lexicographically separable. We show that these social choice functions (which we call generalized random dictatorships) are induced by probability distributions on voter sequences of length equal to the number of components. They induce a fixed probability distribution on the product set of voter peaks. The marginal probability distribution over every component is a random dictatorship. Our results generalize the classic random dictatorship result in Gibbard (1977) and the decomposability results for strategy-proof deterministic social choice functions for multi-dimensional models with separable preferences obtained in LeBreton and Sen (1999).     

Growth in a Cross-section of Cities: Location,Increasing Returns or Random Growth?

Abstract

This article analyses empirically the main existing theories on income and population city growth: increasing returns to scale, locational fundamentals and random growth. To do this we consider a large database of urban, climatological and macroeconomic data from 1,173 US cities observed in 1990 and 2000. The econometric model is robust to the presence of spatial effects. Our analysis shows the existence of increasing returns and two distinct equilibria in per-capita income and population growth. We also find important differences in the structure of productive activity, unemployment rates and geographical location between cities in low-income and high-income regimes.     

ENHANCEMENT OF THE APPLICABILITY OF MARKOWITZ'S PORTFOLIO OPTIMIZATION BY UTILIZING RANDOM MATRIX THEORY

The traditional estimated return for the Markowitz mean-variance optimization has been demonstrated to seriously depart from its theoretic optimal return. We prove that this phenomenon is natural and the estimated optimal return is always       times larger than its theoretic counterpart, where       with  y  as the ratio of the dimension to sample size. Thereafter, we develop new bootstrap-corrected estimations for the optimal return and its asset allocation and prove that these bootstrap-corrected estimates are proportionally consistent with their theoretic counterparts. Our theoretical results are further confirmed by our simulations, which show that the essence of the portfolio analysis problem could be adequately captured by our proposed approach. This greatly enhances the practical uses of the Markowitz mean-variance optimization procedure.     

The Value of Changes in Deer Season Length: An Application of the Nested Multinomial Logit Model

Increasing deer populations can be controlled through manipulatingharvest limits or season length. While such actions often result in benefitsto hunters, both motorists and the agricultural sector also benefit as alower deer population leads to fewer incidences of harmful human-deerencounters. Traditional recreation demand models are often employed toexamine the welfare implications of changes in daily hunting bag limits.Studies measuring the effects of changes in season length, however, arenoticeably absent from the literature. This study uses a nested randomutility model to examine hunter choice over site and season selection toderive the values of changes in season length.     

Equilibrium prices in a random exchange economy with dependent agents

Summary. This paper presents a model of a Walrasian exchange economy in which the preferences and endowments of the agents are random. Stochastic interaction among the agents is formally described in terms of dependency neighborhoods. The main result is a characterization of the distribution of market-clearing prices in a large economy. Received: April 23, 1999; revised version: May 6, 1999     

随机正交变换法在隐私保持关联规则挖掘中的应用

隐私保护是当前数据挖掘领域中一个十分重要的研究方向。本文针对关联规则挖掘中如何保持隐私的问题,采用一种不依赖具体数据的随机正交变换方法,从而解决了在数据集容量很大的情况下,运算量大的问题,并使用传统隐私保护度评价方法与正交变换的方向隐私保护度相结合的方法评价变换的隐私保护度,进而使得结果更符合实际情况。理论分析和论证表明本文中的方法具有很好的隐私性、高效性和适用性。     

Fisher information under Gaussian quadrature models

This paper develops formulae to compute the Fisher information matrix for the regression parameters of generalized linear models with Gaussian random effects. The Fisher information matrix relies on the estimation of the response variance under the model assumptions. We propose two approaches to estimate the response variance: the first is based on an analytic formula (or a Taylor expansion for cases where we cannot obtain the closed form), and the second is an empirical approximation using the model estimates via the expectation–maximization process. Further, simulations under several response distributions and a real data application involving a factorial experiment are presented and discussed. In terms of standard errors and coverage probabilities for model parameters, the proposed methods turn out to behave more reliably than does the ‘disparity rule’ or direct extraction of results from the generalized linear model fitted in the last expectation–maximization iteration.     

The impact of Bus Rapid Transit (BRT) on land and property values: A meta-analysis

Throughout the world, Bus Rapid Transit (BRT) has become a popular transit solution for cities wanting to improve urban mobility and economic opportunities through land and property value uplift (LVU). However, the relevant literature reports a mixed impact of BRT on land and property values. This research aims to explain the variation in impacts by conducting a meta-analysis of 23 empirical studies which have estimated the amount of LVU that is attributable to BRT. Using a random-effects model, four categories of factors that may influence estimates of BRT impacts are analysed: BRT system characteristics; land type and accessibility; research methods; and the spatial and temporal characteristics of the case study. Several factors were found to have a statistically significant impact on estimated LVU impacts from BRT systems including maturity of the BRT system; property or land; type of value (asking price, assessed price or sales price); the distance to BRT stations; the research method; and the geographical location of the BRT system. Using the quantifiability advantages of meta-analysis techniques, we further conducted a broad comparison between our results and the findings from one previous meta-analysis study on Rail-Based Transit (RBT), and discussed how the LVU impact differs between BRT and RBT. The findings from this research suggest several key recommendations for future studies into the impact of BRT on land and property values. They also inform policy analyses on transit funding through land and property value gains.     

On peacocks and lyrebirds: Australian options,Brownian bridges,and the average of submartingales

We introduce a class of stochastic processes, which we refer to as lyrebirds. These extend a class of stochastic processes, which have recently been coined peacocks, but are more commonly known as processes that are increasing in the convex order. We show how these processes arise naturally in the context of Asian and Australian options and consider further applications, such as the arithmetic average of a Brownian bridge and the average of submartingales, including the case of Asian and Australian options where the underlying features constant elasticity of variance or is of Merton jump diffusion type.