The economic burden of kidney disorders in Korea

Aims: To estimate the economic burden of kidney disorders in Korea.

Materials and methods: The economic burden of kidney disorders was estimated using a prevalence-based approach. Related kidney diseases in patients with kidney disorders (RPWKD) were defined using codes from the tenth International Classification of Disease (E70–E90, F30–F48, F60–F69, F90–F99, K65–K67, N00–N08, N17–N19, and N30–N39). All diseases in patients with kidney disorders (APWKD) were defined as kidney disorders that involved all disease codes. Economic costs were divided into direct costs (medical costs and non-medical costs) and indirect costs (productivity loss because of morbidity and premature mortality).

Results: The prevalence of kidney disorders increased from 0.08% (2008) to 0.11% (2011). The total economic burden of RPWKD also substantially increased from $898.9 million (2008) to $1.43 billion (2011). This ～59.4% increase in the economic burden was equal to 0.12% of the Korean gross domestic product. The economic burden of APWKD also increased during the study period: $1.06 billion (2008), $1.23 billion (2009), $1.44 billion (2010), and $1.46 billion (2011).

Conclusions: The present study provides the first data regarding the economic burden of kidney disorders in Korea. The findings support the need for early intervention services and prevention programs to prevent, identify, and manage kidney disorders.     

Market access,supplier access,and Africa's manufactured exports: A firm level analysis

Abstract

In a large cross-country sample of manufacturing establishments drawn from 188 cities, average exports per establishments are smaller for African firms than for businesses in other regions. Based on the estimation of firm level exporting equations, we show that this is mainly because, on average, African firms face more adverse economic geography and operate in poorer institutional settings. One part of the effect of geography operates through Africa's lower ‘foreign market access’: African firms are located further away from wealthier or denser potential export markets. A second occurs through the region's lower ‘supplier access’: African firms face steeper input prices, partly because of their physical distance from cheaper foreign suppliers, and partly because domestic substitutes for importable inputs are more expensive. Africa's poorer institutions reduce its manufactured exports directly, as well as indirectly, by lowering foreign market access and supplier access. Both geography and institutions influence average firm level exports significantly more through their effect on the number of exporters than through their impact on how much each exporter sells onto foreign markets.     

Some Nonlinear Threshold Autoregressive Time Series Models for Actuarial Use

Abstract

This paper introduces nonlinear threshold time series modeling techniques that actuaries can use in pricing insurance products, analyzing the results of experience studies, and forecasting actuarial assumptions. Basic “self-exciting” threshold autoregressive (SETAR) models, as well as heteroscedastic and multivariate SETAR processes, are discussed. Modeling techniques for each class of models are illustrated through actuarial examples. The methods that are described in this paper have the advantage of being direct and transparent. The sequential and iterative steps of tentative specification, estimation, and diagnostic checking parallel those of the orthodox Box-Jenkins approach for univariate time series analysis.     

The performance of traders' rules in options market

This study focuses on the usefulness of the traders' rules to predict future implied volatilities for pricing and hedging KOSPI 200 index options. There are two versions of this approach. In the “relative smile” approach, the implied volatility skew is treated as a fixed function of moneyness. In the “absolute smile” approach, the implied volatility skew is treated as a fixed function of the strike price. It is found that the “absolute smile” approach shows better performance than Black, F. and Scholes, L. ( 1973 ) model and the stochastic volatility model for both pricing and hedging options. Consistent with Jackwerth, J. C. and Rubinstein, M. (2001) and Li, M. and Pearson, N. D. (2007), the traders' rules dominate mathematically more sophisticated model, that is, the stochastic volatility model. The traders' rules can be an alternative to the sophisticated and complicated models for pricing and hedging options. © 2009 Wiley Periodicals, Inc. Jrl Fut Mark 29:999–1020, 2009     

On Evaluating the Performance of Problem Structuring Methods: An Attempt at Formulating a Conceptual Model

In the past decade there has been a discussion on the need for and degree of empirical evidence for the effectiveness of problem structuring methods (PSMs). Some authors propose that PSMs are used in unique situations which are difficult to study, both from a methodological and a practical perspective. In another view experimental validation is necessary and, if not obtained, PSMs remain substantially invalidated and thus ‘suspect’ with regard to their claims of effectiveness. Both views agree on one point: the necessity of being clear about the important factors in the context in which a method is used, the method’s aims and its essential elements through which these aims are achieved. A clear formulation of central variables is the core of a theoretical validation, without which empirical testing of effects is impossible. Since the process of PSMs is sometimes referred to as ‘more art than science’, increased clarity on the PSM process also supports the transfer of methods. In this article we consider goals important to most PSMs, such as consensus and commitment. We then focus on outcomes of group model building, and expectations on how context and group modeling process contributes to outcomes. Next we discuss the similarity of these central variables and relations to two sets of theories in social psychology: the theory of planned behavior and dual process theories of persuasion. On the basis of these theories we construct a preliminary conceptual model on group model building effectiveness and address its practical applicability for research on PSM.     

China's poverty statistics

China's official poverty statistics show a dramatic reduction in poverty from 31% of the rural population in 1978 to 3% in 2000. We evaluate possible sources of bias in these estimates and conclude that the official statistics underestimate rural poverty and overstate the speed of poverty reduction. Direct measures of nutritional outcomes support the contention that poverty is more widespread than suggested by official statistics. Priority should be given to constructing new statistics to accurately measure urban poverty. The method for calculating county income per capita, a key policy variable affecting official poor county designation, is ad hoc and subject to political influence.     

Can the Indicative Price System Mitigate Expiration‐Day Effects?

We investigate whether the indicative price system, introduced in the Korean derivatives market on July 1, 2003, has helped mitigate the options and futures expiration‐day effects. Prior to introduction of this system, we find evidence of high trading volume and significant price reversals during the first half hour of trading for the day immediately following the expiration day. These effects decline significantly after July 1, 2003. Our evidence suggests that the indicative price system can mitigate the expiration‐day effects.     

Employment growth from the Small Business Innovation Research program

This paper investigates employment growth in small firms funded by the U.S. Small Business Innovation Research (SBIR) program. Using data collected by the National Research Council for each of five federal agencies, our analysis shows that on average over two-fifths of all projects retained zero employees after completion and over one-third retained only one or two employees. Thus, on average, the direct impact of SBIR funded projects on employment is small, especially when compared to the mean number of employees in the firms. However, there are substantial cross-project differences in the number of retained employees that are explained by differences in the firms and their SBIR projects. We find across funding agencies that projects with intellectual property??patents, copyrights, trademarks, or publications??retained more employees after completion of the project. Also, we find that the public funding of research by the SBIR program is more likely to stimulate employment when the government created a market for the products, processes, or services developed by the research projects.