Tootfinder

On 102-avoiding inversion sequences
JiSun Huh, Sangwook Kim, Seunghyun Seo, Heesung Shin
https://arxiv.org/abs/2506.02985 https://arx…

On 102-avoiding inversion sequences
In this article, we provide a bijection between the set of inversion sequences avoiding the pattern 102 and the set of 2-Schröder paths having neither peaks nor valleys and ending with a diagonal step. To achieve this, we introduce two intermediate objects, called UVD paths and labeled $F$-paths, and establish bijections among all four families. For each of these combinatorial objects, we define a natural statistic and enumerate the corresponding structures with respect to this statistic. In a…

Get me out of this hole: a profile likelihood approach to identifying and avoiding inferior local optima in choice models
Stephane Hess, David Bunch, Andrew Daly
https://arxiv.org/abs/2506.02722

Get me out of this hole: a profile likelihood approach to identifying and avoiding inferior local optima in choice models
Choice modellers routinely acknowledge the risk of convergence to inferior local optima when using structures other than a simple linear-in-parameters logit model. At the same time, there is no consensus on appropriate mechanisms for addressing this issue. Most analysts seem to ignore the problem, while others try a set of different starting values, or put their faith in what they believe to be more robust estimation approaches. This paper puts forward the use of a profile likelihood approach t…