Multiple linear regression (MLR) is a statistical technique that uses several explanatory variables to predict the outcome of a response variable.

With only one variable in the model, it is unclear whether Visa affects the S&P 500 prices, if the S&P 500 affects V prices, or if some unobserved third variable affects both prices.

Additive models and tree-based regression models are two main classes of statistical models used to predict the ... For sample sizes of 300 ... (2002), "Regression Trees With Unbiased Variable ...

Donald W. K. Andrews, Marcelo J. Moreira, James H. Stock, Optimal Two-Sided Invariant Similar Tests for Instrumental Variables Regression, Econometrica, Vol. 74, No. 3 (May, 2006), pp. 715-752 Free ...