Exponentially weighted information criteria for selecting among forecasting models

Information criteria (IC) are often used to decide between forecasting models. Commonly used criteria include Akaike's IC and Schwarz's Bayesian IC. They involve the sum of two terms: the model's log likelihood and a penalty for the number of model parameters. The likelihood is calculated with equal weight being given to all observations. We propose that greater weight should be put on more recent observations in order to reflect more recent accuracy. This seems particularly pertinent when selecting among exponential smoothing methods, as they are based on an exponential weighting principle. In this paper, we use exponential weighting within the calculation of the log likelihood for the IC. Our empirical analysis uses supermarket sales and call centre arrivals data. The results show that basing model selection on the new exponentially weighted IC can outperform individual models and selection based on the standard IC.     

基于实例的水资源预测方法概述

基于合肥市近几年的城市生活用水量数据为例,对一些水资源预测方法进行讨论和比较。对合肥市城市生活用水量的现状进行简要的概述;介绍三种水资源预测方法即指数平滑法、灰色模型预测法和BP神经网络预测法的理论方法及模型;利用给定的资料数据,运用三种预测方法进行分析,通过拟和模型误差对比,判定最佳的预测方法。     

Non-parametric estimation of operational risk losses adjusted for under-reporting

Not all claims are reported when a database for financial operational risk is created. The probability of reporting increases with the size of the operational risk loss, and converges towards one for big losses. Losses in operational risk have different causes, and usually follow a wide variety of distributional shapes. Therefore, a method for modelling operational risk based on one or two parametric models is deemed to fail. In this paper, we introduce a semi-parametric method for modelling operational risk that is capable of taking under-reporting into account and being guided by prior knowledge of the distributional shape.     

Inflation Targeting: Some Extensions

Previous analyses of the implementation of inflation targeting are extended to monetary policy responses to different shocks, consequences of model uncertainty, and effects of interest rate smoothing and stabilization. Model uncertainty, output stabilization, and interest rate stabilization or smoothing all call for a more gradual adjustment of the conditional inflation forecast toward the inflation target. The conditional inflation forecast is the natural intermediate target during inflation targeting. The optimal way of reacting to shocks is hence to check how they affect the inflation forecast and then take the appropriate action.
JEL classification : E 42; E 52; E 58     

Demand for cash with intra-period endogenous consumption

We extend the literature on the demand for money by relaxing the assumption of a constant rate of consumption. Although total consumption is still fixed over the period, agents can choose more than one rate of consumption and cash depletion in the period to minimize the cost of money management. Consistent with empirical evidence, we find that agents do not smooth intra-period consumption. Instead, their rate of consumption will be positively related to their cash position. This positive correlation depends on the volatility of the consumption process.     

The poverty of solidarity: the size and structure of informal income smoothing among worker households in Helsinki, 1928

Abstract

Informal income smoothing by households before the post-Second World War expansion in public welfare has gained attention in the history of poverty and social insurance. Little direct empirical evidence has been available. Finnish household budgets from 1928 with intra-year panel data on informal transactions enable analysis of the use of savings, loans and informal assistance to counter income variation by worker families in Helsinki. Income shares of transfers were small compared with labour-based methods of supplementing the earnings of the surveyed male breadwinner families. Within the year, however, the combined use of assistance, credit, and savings accounts compensated on average 36% of income fluctuations, while means such as added workers or taking in lodgers appeared ineffective on the short run. Informal assistance mattered for the poorest households, but provided inferior coverage compared with that attained through credit and savings by more affluent workers. Income inequality was therefore replicated as risk-management inequality.     

Relevance weighted likelihood for dependent data

The relevance-weighted likelihood function weights individual contributions to the likelihood according to their relevance for the inferential problem of interest. Consistency and asymptotic normality of the weighted maximum likelihood estimator were previously proved for independent sequences of random variables. We extend these results to apply to dependent sequences, and, in so doing, provide a unified approach to a number of diverse problems in dependent data. In particular, we provide a heretofore unknown approach for dealing with heterogeneity in adaptive designs, and unify the smoothing approach that appears in many foundational papers for independent data. Applications are given in clinical trials, psychophysics experiments, time series models, transition models, and nonparametric regression. Received: April 2000     

How does the sensitivity of consumption to income vary over time? International evidence

This paper studies how the sensitivity of consumption to income has changed over time as the degree of financial integration has risen. In standard theory, greater financial integration facilitates international borrowing and lending, helping to reduce the sensitivity of consumption growth to fluctuations in income. We examine the empirical validity of this prediction using an array of indicators of financial integration for a large sample of advanced and developing countries over the period 1960–2011. We report two main results. First, the sensitivity of consumption to income has declined over time as the degree of financial integration has risen. The decline has been more pronounced in advanced economies than in developing ones. Second, our regression analysis indicates that a higher degree of financial integration is associated with a lower sensitivity of consumption to income. This finding is robust to the use of a wide range of empirical specifications, country-specific characteristics and other controls, such as interest rates and outcome-based measures of financial integration. We also discuss other potential sources of the temporal changes in the sensitivity of consumption to income.     

我国产险业未决赔款准备金修饰盈余实证研究

2005年以前,产险公司根据财务制度提存未决赔款准备金,使公司极易通过提存未决赔款准备金的方式修饰盈余.因此,本文实证分析产险公司财务报表中未决赔款准备金数额与公司运营结果之间的关联性,揭示公司调整未决赔款准备金的动机.结果表明,在财务制度规定下,产险公司确实存在故意调整未决赔款准备金数字,以实现扩张盈余修饰空间的目的.