Discovering bank risk factors from financial statements based on a new semi‐supervised text mining algorithm

This paper aims to comprehensively uncover bank risk factors from qualitative textual risk disclosures reported in financial statements, which contain a huge amount of information on bank risks. We propose a new semi‐supervised text mining approach named naive collision algorithm to analyse the textual risk disclosures, which can more accurately identify bank risk factors compared with the typical unsupervised text mining approach. We identified 21 bank risk factors in total, which is far more than identified in previous studies. We further analyse the importance of each bank risk factor and how the importance of each risk factor changes over time.     

Is econometrics useful for private policy making? A case study of replacement policy at an auto rental company

The goal of this paper is to illustrate the potential usefulness of econometrics as a tool to assist private policy makers. We provide a case study and detailed econometric analysis of the automobile replacement policy adopted by a large car rental company. Unlike public policy making–where the benefits from using econometric models and “science-based” approaches to policy making are hard to quantify because the outcomes of interest are typically subjective quantities such as “social welfare”–in the case of firms there is an objective, easily quantifiable criterion for judging whether policy A is better than policy B: profits. We introduce and estimate an econometric model of the rental histories of individual cars in the company’s fleet. Via stochastic simulations, we show that the model provides a good approximation to the company’s actual operations. In particular, the econometric model is able to reproduce the extraordinarily high rates of return that the company obtains on its rental cars, with average internal rates of return between purchase and sale of approximately 50%. However, the econometric model can simulate outcomes under a range of counterfactual vehicle replacement policies. We use the econometric model to simulate the profitability of an alternative replacement policy under pessimistic assumptions about the rate maintenance costs would increase and rental rates would have to be decreased if the company were to keep its rental cars longer than it does under the status quo. Depending on the vehicle type, we find that the company’s expected discounted profits would be between 6% to over 140% higher under the suggested alternative operating strategy where vehicles are kept longer and rental rates of older vehicles are discounted to induce customers to rent them. The company found this analysis to be sufficiently convincing that it undertook an experiment to verify the predictions of the econometric model.     

Analysing Tax–Benefit Reforms Using Non‐Parametric Methods*

Static tax–benefit microsimulation models (MSMs) are widely used and well‐regarded tools for public policy analysis, but it is essential to use them very carefully. This paper focuses on the analysis of MSM output, suggesting the use of non‐parametric methods as a useful, informative and relatively straightforward complement to detect effects not always captured by measures often used to present MSM results. Non‐parametric methods are used here to analyse the output of an MSM applied to the 1998 Italian personal income tax reform, the main change in which concerned the tax schedule: the first tax rate was increased from 10 per cent to 18.5 per cent and the top one was reduced by 4.5 percentage points. Non‐parametric methods highlight that the effects of this reform were very different for different types of households, with low‐income pensioner households among the main losers. Results are checked for robustness by standard statistical methods and compared with empirical results obtainable using quintile histograms.     

PRODUCTIVE EFFICIENCY IN THE IVORIAN MANUFACTURING SECTOR: AN EXPLORATORY STUDY USING A DATA ENVELOPMENT ANALYSIS APPROACH

The African industrial structure is characterized by firm‐size heterogeneity with the coexistence of small, if not micro, enterprises in the informal sector and large formal organizations operating with modern technology. In this paper, using the Data Envelopment Analysis production frontier methodology, we investigate the technical efficiency of Ivorian manufacturing firms in four sectors of economic activity: textiles and garments, metal products, food processing, and wood and furniture. Efficiency scores are adjusted to take into account the impact of the external operating environment. These scores are then broken down into three elements: the purely managerial effect, the impact of the scale of production, and a technological effect capturing the potential gain that could result from the adoption of modern technology by small informal organizations. Not only formal activities prove to be more efficient in scaling their production but also, they greatly benefit from their modem technology.     

THE EFFECT OF ACCESS TO IMPROVED WATER SOURCES AND SANITATION ON ECONOMIC EFFICIENCY: THE CASE OF SUB‐SAHARAN AFRICAN COUNTRIES

This paper evaluates the effect of access to improved water sources and sanitation on 41 sub‐Saharan African (SSA) countries' economic efficiency and growth. For this reason data envelopment analysis (DEA), bootstrap techniques and probabilistic approaches are used. The empirical results indicate that SSA countries' economic efficiency is positively influenced by the access of population both on improved water sources and sanitation. Finally, when the provision of access to improved water sources is provided to more than 50% of the population, the positive effect on countries' economic efficiency is much greater compared with the effect of providing sustainable access to improved sanitation to the same proportion of population.     

DEA APPLIED TO A GAUTENG SAMPLE OF PUBLIC HOSPITALS1

The research presented in this paper provides an analysis of the delivery of a few health care services by the public sector in Gauteng, South Africa. The data for the study was especially difficult to collect, suggesting the need for hospital level data information systems, as well as staff who are trained to analyze the information collected. The empirical results from the analysis suggest that services provided by small‐scale medical facilities waste fewer resources, while medical centres offering more technical services, such as surgeries, also appear to deliver medical services more efficiently.     

Existence,uniqueness, and stability of optimal payoffs of eligible assets

In a capital adequacy framework, risk measures are used to determine the minimal amount of capital that a financial institution has to raise and invest in a portfolio of prespecified eligible assets in order to pass a given capital adequacy test. From a capital efficiency perspective, it is important to be able to do so at the lowest possible cost and to identify the corresponding portfolios, or, equivalently, their payoffs. We study the existence and uniqueness of such optimal payoffs as well as their behavior under a perturbation or an approximation of the underlying capital position. This behavior is naturally linked to the continuity properties of the set‐valued map that associates to each capital position the corresponding set of optimal eligible payoffs. Upper continuity can be ensured under fairly natural assumptions. Lower continuity is typically less easy to establish. While it is always satisfied in a polyhedral setting, it generally fails otherwise, even when the reference risk measure is convex. However, lower continuity can often be established for eligible payoffs that are close to being optimal. Besides capital adequacy, our results have a variety of natural applications to pricing, hedging, and capital allocation problems.     

Exact parametric restrictions for 3-cycles in the RSS model: A complete and comprehensive characterization

This paper presents necessary and sufficient conditions for 3-period cycles in the two-sector Robinson–Solow–Srinivasan (RSS) model, taking as its point of departure an independently-(and simultaneously-) discovered exact discount-factor restriction for a general class of growth models by Mitra and Nishimura–Yano (MNY) in 1996. Our investigation of this remarkable result in the specificity of the RSS model enables a broadened inquiry that goes beyond the discount factor to parameters of labor-productivity and capital-depreciation. Since the RSS model, despite its concrete simplicity, is not covered by the general MNY model, the exact discount-factor restriction presented here does not follow from the MNY theorem, and necessitates new argumentation. Furthermore, we present a novel exact parametric region as our second result.     

TOTAL FACTOR PRODUCTIVITY ESTIMATION: A PRACTICAL REVIEW

Abstract This paper aims to provide empirical researchers with an overview of the methodological issues that arise when estimating total factor productivity at the establishment level, as well as of the existing (parametric and semi‐parametric) techniques designed to overcome them. Apart from the well‐known simultaneity and selection bias, attention is given to methodological issues that have emerged more recently and that are related to the use of deflated values of inputs and outputs (as opposed to quantities) in estimating productivity at the firm level, as well as to the endogeneity of product choice. In discussing the estimation procedures applied in the literature, attention is given to recent developments in the field. Using data on single‐product firms active in the Belgian food and beverages sector, the most commonly applied estimators are illustrated, allowing for comparison of the obtained productivity estimates by way of a simple evaluation exercise.     

Bootstrap inference using estimating equations and data that are linked with complex probabilistic algorithms

Probabilistic record linkage is the act of bringing together records that are believed to belong to the same unit (e.g., person or business) from two or more files. It is a common way to enhance dimensions such as time and breadth or depth of detail. Probabilistic record linkage is not an error-free process and link records that do not belong to the same unit. Naively treating such a linked file as if it is linked without errors can lead to biased inferences. This paper develops a method of making inference with estimating equations when records are linked using algorithms that are widely used in practice. Previous methods for dealing with this problem cannot accommodate such linking algorithms. This paper develops a parametric bootstrap approach to inference in which each bootstrap replicate involves applying the said linking algorithm. This paper demonstrates the effectiveness of the method in simulations and in real applications.