Why we like the ECI+ algorithm

TL;DR

This paper demonstrates that the ECI+ algorithm is mathematically equivalent to the Fitness algorithm for Economic Complexity, clarifies misconceptions about their capabilities, and discusses potential errors in prior claims due to improper implementation.

Contribution

It reveals the mathematical equivalence between ECI+ and Fitness algorithms and corrects misconceptions about their effectiveness in measuring economic complexity.

Findings

ECI+ is mathematically identical to the Fitness algorithm

Incorrect claims about Fitness's ability to measure economic complexity

Potential errors arise from not iterating the algorithm properly

Abstract

Recently a measure for Economic Complexity named ECI+ has been proposed by Albeaik et al. We like the ECI+ algorithm because it is mathematically identical to the Fitness algorithm, the measure for Economic Complexity we introduced in 2012. We demonstrate that the mathematical structure of ECI+ is strictly equivalent to that of Fitness (up to normalization and rescaling). We then show how the claims of Albeaik et al. about the ability of Fitness to describe the Economic Complexity of a country are incorrect. Finally, we hypothesize how the wrong results reported by these authors could have been obtained by not iterating the algorithm.