Joint pricing and inventory control for non-instantaneous deteriorating items with partial backlogging and time and price dependent demand

In this paper, a joint pricing and inventory control for non-instantaneous deteriorating items is developed. We adopt a price and time dependent demand function. Shortages is allowed and partially backlogged. The major objective is to determine the optimal selling price, the optimal replenishment schedule and the optimal order quantity simultaneously such that, the total profit is maximized. We first show that for any given selling price, optimal replenishment schedule exists and unique. Then, we show that the total profit is a concave function of price. Next, we present a simple algorithm to find the optimal solution. Finally, we solve a numerical example to illustrate the solution procedure and the algorithm.     

Natural resource rents and internal conflicts: Can decentralization lift the curse?

We study how natural resource rents affect the risk of internal conflict within countries and how the federal structure of countries influences this relationship. Natural resource abundance may induce excessive rent-seeking and thus increase the risk of internal conflict. Fiscal and political decentralization as an institutional arrangement for rent-sharing and political codetermination of regions within a country may limit the destructive effect of natural resource rents on internal stability. Using cross-country and panel data from more than 90 countries covering the period 1984–2004, we find evidence that natural resource rents indeed increase the risk of internal conflict, but this relationship is significantly mitigated by political decentralization.     

The impact on stock prices of deferral and elimination of internal control audit requirement for small firms

This paper examines the cumulative market reaction to the events related to deferral of internal control audit requirement under the Sarbanes-Oxley Act of 2002 and its elimination under the Dodd-Frank Act of 2010 for nonaccelerated filers (small firms). We document that small firms experienced negative cumulative abnormal returns around these events; and the differences between the cumulative abnormal returns for small firms and the two control groups (accelerated and large accelerated filers) were negative and significant at the 1% level. These results support the notion that market participants value the reliability of financial information irrespective of the firm size. Within the small firms, we find no firm characteristic significantly explains the market reaction to the events considered. That is, all small firms lost market value in reaction to the events that delayed and eliminated their internal control audit requirement.     

A Hybrid Fuzzy-Probabilistic Bargaining Approach for Multi-objective Optimization of Contamination Warning Sensors in Water Distribution Systems

Group Decision and Negotiation - Water Distribution System (WDS) are strategic infrastructures in all countries. In recent decades, several optimization-based frameworks have been developed to...     

Dynamic lot sizing problem with continuous-time Markovian production cost

This paper develops a polynomial algorithm for obtaining dynamic economic lot sizes in a single product multiperiod production system with the objective of minimizing total production and inventory costs over T periods. It is assumed that production costs are linear, inventory costs are concave, setup costs are zero and backlogging is not permitted in all periods. Moreover, the unit production cost is a stochastic variable, which is evolved according to a continuous-time Markov process over the planning horizon. The model is formulated as a stochastic dynamic programming (DP) optimization with the state variable being unit production cost. Then, it is solved using the backward dynamic programming approach. To justify the application of the proposed model, two practical cases are presented.     

Investor legal protection and earnings management: A study of Chinese H-shares and Hong Kong shares

Under the unique “one country, two systems” arrangement, the more stringent investor protection rules in Hong Kong are not enforceable in firms that are incorporated in China but listed on the Hong Kong stock exchange (H-shares). As such, H-shares and other local Hong Kong firms are subject to different investor protection regimes in the same stock market. We find that H-shares are associated with higher earnings management than local Hong Kong firms after controlling for disparity in economic development, types of controlling shareholders and other factors. More importantly, this relationship is weaker after China implemented the Securities Law in 1999. The results are robust after considering the dual-listing status of H-shares and board characteristics. These results provide direct evidence showing the effect of investor legal protection on financial reporting quality.     

An empirical study of the determinants of UK oil and gas voluntary disclosures

Significant oil and gas firm market value is derived from their physical reserve quantum, assets which are not recorded on their statements of financial position. This article provides empirical evidence regarding voluntary disclosure of such reserves in line with the previously unresearched UK sector with regard to its unique reporting guidelines. The study considers both the reporting of the reserve quantum and the quality of that reporting. This article seeks to inform the International Accounting Standards Board’s (IASB’s) on-going consideration of mineral resource reporting. Listed companies are considered to evidence forms of reserve disclosure with a logistical regression approach applied to measure determinants of reporting. The risk associated with mineral reporting reserves is hypothesized as the key disclosure driver whilst controlling other relevant variables. The majority of firms disclosed reserve quantities in some form but only a minority disclosed in line with recommended practice, disclosure quality being more variable between companies. The findings indicate that a voluntary disclosure approach is ineffective, partially explained by agency related behaviour. Risk, proxied by the stage of production, drives reserve disclosure showing that producer firms are more likely to disclose reserve quantum balances and of a significantly higher quality.     

Getting ahead or falling behind: Findings from the second wave of the National Income Dynamics Study

The National Income Dynamics Study is the first national panel study of South African individuals. Its objective is to track these individuals over time to study social mobility. This paper documents the survey design and a successful recontact record in Wave 2 before providing an overview of the key findings from the other papers in this issue of the journal. Those from the top of the income distribution were hardest to recontact. The papers show that average real incomes grew slightly between 2008 and 2010. However, life satisfaction and expectations of future upward mobility declined. Being unemployed and moving into unemployment is associated with the lowest level of life satisfaction. Aggregate employment did not decline much but there was significant labour-market churn. The National Income Dynamics Study data reveal high levels of grade repetition and a slow transition from school to work. Relocating is shown to be an important part of schooling and employment decisions.     

Wealth data quality in the National Income Dynamics Study Wave 2

This paper examines the quality of data on household assets, liabilities and net worth in the South African National Income Dynamics Study (NIDS) Wave 2. The NIDS is the first nationally representative survey on household wealth in South Africa. The cross-sectionally weighted data are found to be fit for use in terms of the univariate distributions of net worth, assets and liabilities, but population totals are probably underestimated due to the presence of missing wealth data in Phase 2 of Wave 2 that is not taken into account in the weights. When compared with national accounts estimates of household net worth, there is an apparent inversion of the estimated totals of financial assets versus non-financial assets. Further research is required into why this is so. We find that the NIDS wealth module is a suitable instrument for the analysis of household wealth.     

Entrepreneurship: Cause and Consequence of Financial Optimism

Extant evidence that the self‐employed overestimate their returns by a greater margin than employees is consistent with two mutually inclusive possibilities. Self‐employment may foster optimism or intrinsic optimists may be drawn to self‐employment. Previous research is generally unable to disentangle these effects because of reliance on cross‐sectional data. Using longitudinal data, this paper finds that employees who will be self‐employed in the future overestimate their short‐term financial wellbeing by more than those who never become self‐employed. Optimism is higher still when self‐employed. These results suggest that the greater optimism of the self‐employed reflects both psychological disposition and environmental factors. By providing greater scope for optimism, self‐employment entices the intrinsically optimistic.