R users can often solve optimization tasks easily using the tools in the optim function in the stats package provided by default on R installations. However, there are many other optimization and nonlinear modelling tools in R or in easily installed add-on packages. These present users with a...

In the wake of Dub´e, Fox and Su (2012), this paper (i) analyzes the consequences for the BLP Contraction Mapping (Berry, Levinsohn and Pakes, 1995) of setting the inner-loop convergence tolerance at the required level of in D 10 14 to avoid propagation of approximation error from inner to...