The α-stable processes and their relationship with the exponent of self-similarity: Exchange rates of USA Dollar,Canadian Dollar,Euro and Yen

This research work analyzes the yields of the exchange rate parities of the American dollar, Canadian dollar, Euro, and Yen; estimates the basic statistics and the α-stables; carries out the Kolmogorov–Smirnov, Anderson–Darling, and Lilliefors goodness of fit tests; estimates the self-similar exponents and carries out the t and F tests, ruling out that the series of parities are multifractal. It also estimates the confidence intervals of the exchange rate parities and concludes that the estimated α-stable distributions are more efficient than the Gaussian distribution to quantify the risks of the market, and that the series are self-similar. Through the ? index, we can infer the risk of the events, indicating that the parities are anti-persistent and thus have short-term memory, mean reversion, and a negative correlation with the high risk in the short and medium term. The estimation and validation of the α-stable distributions and the self-similar exponent are important in the evaluation and creation of innovative investment instruments through financial engineering, risk administration, and the evaluation of derived products.     

The spanish restaurant sector: evaluating the perceptions of quality

The restaurant sector is one of the fastest growing sectors within the Spanish economy and looks likely to continue its development into the future. The implementation of total quality (TQ) systems in the tourist industry is still a recent phenomenon in Spain. Hence the importance of the client's satisfaction, resulting in the acquisition of an optimum quality level: i.e. cooking is culture and it has to be culturally adapted and promoted. The survey on the customers of Spanish restaurants reported in this article has gathered the perception of quality according to a likert scale from one to five. The objective of the survey was to determine the degree of satisfaction as well as the quality of the establishment, by using a cluster analysis of the data. Amongst the findings of the survey was the importance of the motivation of pleasure that makes people go to restaurants and it is therefore necessary to create a favourable atmosphere of quality the customers will want to come back to. This provides the sector's greatest challenge.     

Convergence in OECD countries: technical change,efficiency and productivity

The aim of this study is to analyse labour productivity convergence in the OECD countries over the period 1975-90. A nonparametric frontier approach is used to calculate the Malmquist productivity index. By breaking it down, the contribution in the growth of labour productivity of technical progress, of changes in efficiency, and of the accumulation of inputs per worker are quantified. Unlike other studies, the results obtained show that technical change has worked against labour productivity convergence, since it has always been greater in the countries with higher labour productivity.     

Venture Capital in Spain by Stage of Development

This paper examines the investment decisions of 51 Spanish venture capital firms by stage of development. The results showed that venture capitalists ranked evaluation criteria related to the characteristics of the entrepreneurs, manager background, and management team experience as more important than market and product characteristics. Factors affecting the required rate of return were more important for the early-stage firms than for late-stage firms. Discounted cash flow analysis is the most frequently used valuation method. Private venture capital firms invest more during late development stages, while public venture capital firms invest more during the early stages. The results can be used by firms seeking venture capital, venture capital firms, consultants, and support agencies that provide capital-acquisition assistance. By gaining insight into decision criteria and processes, firms can develop better and more targeted materials to attract capital. Venture capital firms can use the information from this study to better understand their decision processes, individually and relative to competitors. Consultants and support agencies can use the information to provide better advice to both firms and venture capital firms. Information is this study could easily be built into training programs for both new and existing businesses. Finally, the results can also be incorporated directly into university courses that include material related to venture capital.     

Economic evaluation of BST-CarGel as an adjunct to microfracture vs microfracture alone in knee cartilage surgery

Objectives:

Knee cartilage damage is a common cause of referral for orthopedic surgery. Treatment aims to reduce pain and symptoms by repairing cartilage. Microfracture, the current standard of care, yields good short-term clinical outcomes; however, treatment might fail after 2–3 years. A Chitosan-Beta glycerolphosphate-based medical device (BST-CarGel) is used as an adjunct to microfracture and demonstrates improvements in quantity and quality of repaired tissue, potentially reducing the risk of treatment failure. This study aimed to establish the economic value of BST-CarGel vs microfracture alone in knee cartilage repair from the societal perspective, using Germany as the reference market.

Methods:

A decision tree with a 20-year time-horizon was constructed, in which undesirable clinical events were inferred following initial surgery. These events consisted of pain management, surgery, and total knee replacement. Clinical outcomes were taken from the pivotal clinical trial, supplemented by other literature. Data and assumptions were validated by a Delphi panel. All relevant resource use and costs for procedures and events were considered.

Results:

In a group of patients with all lesion sizes, the model inferred that BST-CarGel yields a positive return on investment at year 4 (with 20-year cumulative cost savings of €6448). Reducing the incremental risk of treatment failure gap between the device and microfracture by 25–50% does not alter this conclusion. Cost savings are greatest for patients with large lesions; results for patients with small lesions are more modest.

Limitations:

Clinical evidence for microfracture and other interventions varies in quality. Comparative long-term data are lacking. The comparison is limited to microfracture and looks only at costs without considering quality-of-life.

Conclusion:

BST-CarGel potentially represents a cost-saving alternative for patients with knee cartilage injury by reducing the risk of clinical events through regeneration of chondral tissue with hyaline characteristics. Since the burden of this condition is high, both to the patient and society, an effective and economically viable alternative is of importance.