HEC Paris

About: HEC Paris is a education organization based out in Jouy-en-Josas, France. It is known for research contribution in the topics: Market liquidity & Entrepreneurship. The organization has 584 authors who have published 2756 publications receiving 104467 citations. The organization is also known as: Ecole des Hautes Etudes Commerciales & HEC School of Management Paris.

Prediction of clinical outcome with microarray data: a partial least squares discriminant analysis (PLS-DA) approach

Abstract: Partial least squares discriminant analysis (PLS-DA) is a partial least squares regression of a set Y of binary variables describing the categories of a categorical variable on a set X of predictor variables. It is a compromise between the usual discriminant analysis and a discriminant analysis on the significant principal components of the predictor variables. This technique is specially suited to deal with a much larger number of predictors than observations and with multicollineality, two of the main problems encountered when analysing microarray expression data. We explore the performance of PLS-DA with published data from breast cancer (Perou et al. 2000). Several such analyses were carried out: (1) before vs after chemotherapy treatment, (2) estrogen receptor positive vs negative tumours, and (3) tumour classification. We found that the performance of PLS-DA was extremely satisfactory in all cases and that the discriminant cDNA clones often had a sound biological interpretation. We conclude that PLS-DA is a powerful yet simple tool for analysing microarray data.

Differences between Domestic Accounting Standards and IAS: Measurement, Determinants and Implications

Abstract: This study analyzes determinants and effects of differences between Domestic Accounting Standards (DAS) and International Accounting Standards (IAS). We use an extensive list of differences between DAS and IAS to create two indices, absence and divergence. Absence measures the extent to which the rules regarding certain accounting issues are missing in DAS but are covered in IAS. Divergence applies in circumstances where the rules regarding the same accounting issue differ in DAS and IAS. It measures the extent of differences between DAS-based rules and IAS-based rules. Using a sample of 30 countries for 2001, we show that absence is (mainly) determined by the importance of the equity market and ownership concentration, while divergence is positively associated with the level of economic development and the importance of the accounting profession, but is constrained by the importance of equity markets. Our analysis suggests that a higher level of absence implies more opportunities for earnings management and for decreases in firm-specific information to investors. A larger divergence from IAS is associated with richer firm-specific information in capital markets.