On the need to address fixed-parameter issues before applying random parameters: A simulation-based study

Numan Ahmad

doi:10.1016/j.amar.2023.100314

On the need to address fixed-parameter issues before applying random parameters: A simulation-based study

2024-03-01

0

PRE

AI

DOI：10.1016/j.amar.2023.100314

Original

Original request for help

Save

Abstract

En 中文

Count regression models have been applied to model expected crash frequency at individual roadway locations. Random parameters have been increasingly integrated into these models to account for unobserved heterogeneity. However, the introduction of random parameters might also mask issues in the model specification, leading to inaccurate relationships and model interpretation. Two of these specification-related issues are: (1) not considering the appropriate functional form of explanatory variables; and, (2) ignoring the best set of significant explanatory variables. To better examine the need for careful model specification, this study uses synthetic data to demonstrate that the consideration of random parameters does not address the two model specification issues identified. The results from the simulation study illustrate that (a) model specification issues cannot be circumvented by random parameters alone and (b) random parameter models including the exhaustive set of explanatory variables available offer significant model improvements.

Keywords:

Random parameter negative binomial

regression

Model specification

Unobserved heterogeneity

Synthetic data

Simulation -based statistical analysis

On the need to address fixed-parameter issues before applying random parameters: A simulation-based study

Abstract

Journal

Organization