MULTIVARIATE WAVELET-BASED SHAPE PRESERVING ESTIMATION
FOR DEPENDENT OBSERVATIONS
COSMA, A. *, SCAILLET, O. **, and VON SACHS, R.***
* Instituto di finanza, University of Lugano
    ** HEC, University of Geneva and FAME
    *** Institut de statistique, Université catholique de Louvain
Abstract
We present a new approach on shape preserving 
  estimation of probability distribution and density functions using wavelet methodology 
  for multivariate dependent data. Our estimators preserve shape constraints such 
  as monotonicity, positivity and integration to one, and allow for low spatial 
  regularity of the underlying functions. As important application, we discuss 
  conditional quantile estimation for financial time series data. We show that 
  our methodology can be easily implemented with B-splines, and performs well 
  in a finite sample situation, through Monte Carlo simulations, using a data-driven 
  choice of the resolution level.
Keywords : Conditional quantile, time series, shape preserving wavelet estimation, B-splines, multivariate process.
JEL : C14, C15, C32.
MSC 2000 : 62G05, 62G07, 42C40, 41A15.