arXiv subjects

Lien Pham

Publications and source records attributed to Lien Pham.

4 recordsLinked to original sources

arXiv2025

Trade Networks and the Rise of a Dominant Currency

We develop a model where currency issuers provide liquidity, while users in a trade network choose currency usage for trade settlement. We identify a feedback mechanism where a user's currency preference spillovers to others and increases the issuer's commitment to liquidity provision, which in turn increases the adoption of the currency. Our findings highlight not only the advantage of the incumbent issuer in maintaining dominance, but also the conditions that lead to the rise and fall of dominant currencies. Our framework offers testable implications for the share of global settlement currencies, the network structure, and the strategy of issuers.

econ.TH↗

arXiv2024

An Iterative Approach to Topic Modelling

Topic modelling has become increasingly popular for summarizing text data, such as social media posts and articles. However, topic modelling is usually completed in one shot. Assessing the quality of resulting topics is challenging. No effective methods or measures have been developed for assessing the results or for making further enhancements to the topics. In this research, we propose we propose to use an iterative process to perform topic modelling that gives rise to a sense of completeness of the resulting topics when the process is complete. Using the BERTopic package, a popular method in topic modelling, we demonstrate how the modelling process can be applied iteratively to arrive at a set of topics that could not be further improved upon using one of the three selected measures for clustering comparison as the decision criteria. This demonstration is conducted using a subset of the COVIDSenti-A dataset. The early success leads us to believe that further research using in using this approach in conjunction with other topic modelling algorithms could be viable.

cs.LG↗

arXiv2023

Translating Natural Language Queries to SQL Using the T5 Model

This paper presents the development process of a natural language to SQL model using the T5 model as the basis. The models, developed in August 2022 for an online transaction processing system and a data warehouse, have a 73\% and 84\% exact match accuracy respectively. These models, in conjunction with other work completed in the research project, were implemented for several companies and used successfully on a daily basis. The approach used in the model development could be implemented in a similar fashion for other database environments and with a more powerful pre-trained language model.

cs.DB↗

arXiv2022

Pecuniary Externality, Ideology and Sphere of Influence

We build a game-theoretic model to formalize Kindleberger's (1996) idea of the public good of leadership. Two superpowers use ideology to compete for influence by forming clubs whose members benefit more when their orientations are closer to the club's. Pecuniary externalities create complementarity among non-superpowers. Their collective agency forces superpower to compromise by choosing an orientation not aligned with its own. We find that superpowers compromise most when expanding their clubs but less as members become more dependent. Moreover, increased member endowments do not always enlarge the club; disproportionate growth by a few can instead contract it.

econ.GN↗