Near-ideal model selection by ℓ1 minimization

By E.J. Candes, Yaniv Plan. 2008

234 citations recorded by the source corpus.

We consider the fundamental problem of estimating the mean of a vector y=Xβ+z, where X is an n×p design matrix in which one can have far more variables than observations, and z is a stochastic error term -— the so-called “p>n” setup. When β is sparse, or, more generally, when there is a sparse subset of covariates providing a close approximation to the unknown mean vector, we ask whether or not it is possible to accurately estimate Xβ using a computationally tractable algorithm. We show that, in a surprisingly wide range of situations, the lasso happens to nearly select the best subset of variables. Quantitatively speaking, we prove that solving a simple quadratic program achieves a squared error within a logarithmic factor of the ideal mean squared error that one would achieve with an oracle supplying perfect information about which variables should and should not be included in the model. Interestingly, our results describe the average performance of the lasso; that is, the performance one can expect in an vast majority of cases where Xβ is a sparse or nearly sparse superposition of variables, but not in all cases. Our results are nonasymptotic and widely applicable, since they simply require that pairs of predictor variables are not too collinear.

Subfields: Artificial Intelligence, Statistics and Probability

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Artificial Intelligence

  1. Sara A. van de Geer
  2. Robert Tibshirani
  3. Victor Chernozhukov
  4. Peter Buhlmann
  5. Jonathan E. Taylor
  6. E.J. Candes
  7. Cun-Hui Zhang
  8. Alexandre Belloni

In Statistics and Probability

  1. Victor Chernozhukov
  2. Robert Tibshirani
  3. E.J. Candes
  4. Sara A. van de Geer
  5. Jonathan E. Taylor
  6. Cun-Hui Zhang
  7. Stefan Wager
  8. Peter Buhlmann

Citations in the corpus