Discussion Papers 2018

CIRJE-F-1101	"Term Structure Models During the Global Financial Crisis: A Parsimonious Text Mining Approach"
Author Name	Nishimura, Kiyohiko G., Seisho Sato and Akihiko Takahashi
Date	October 2018
Full Paper	PDF File
Remarks	Revised in December 2018; forthcoming in Asia-Pacific Financial Market.

Abstract
This work develops and estimates a three-factor term structure model with explicit sentiment factors in a period including the global financial crisis, where market confidence was said to erode considerably. It utilizes a large text data of real time, relatively high-frequency market news and takes account of the difficulties in incor- porating market sentiment into the models. To the best of our knowledge, this is the first attempt to use this category of data in term-structure models. Although market sentiment or market confidence is often regarded as an important driver of asset markets, it is not explicitly incorporated in traditional empirical factor models for daily yield curve data because they are unobservable. To overcome this problem, we use a text mining approach to generate observable variables which are driven by otherwise unobservable sentiment factors. Then, applying the Monte Carlo filter as a filtering method in a state space Bayesian filtering approach, we estimate the dynamic stochastic structure of these latent factors from observable variables driven by these latent variables. As a result, the three-factor model with text mining is able to distinguish (1) a spread-steepening factor which is driven by pessimists' view and explaining the spreads related to ultra-long term yields from (2) a spread- attening factor which is driven by optimists' view and in uencing the long and medium term spreads. Also, the three-factor model with text mining has better fitting to the observed yields than the model without text mining. Moreover, we collect market participants' views about specific spreads in the term structure and find that the movement of the identified sentiment factors are consistent with the market participants' views, and thus market sentiment.

Abstract

This work develops and estimates a three-factor term structure model with explicit sentiment factors in a period including the global financial crisis, where market confidence was said to erode considerably. It utilizes a large text data of real time, relatively high-frequency market news and takes account of the difficulties in incor- porating market sentiment into the models. To the best of our knowledge, this is the first attempt to use this category of data in term-structure models. Although market sentiment or market confidence is often regarded as an important driver of asset markets, it is not explicitly incorporated in traditional empirical factor models for daily yield curve data because they are unobservable. To overcome this problem, we use a text mining approach to generate observable variables which are driven by otherwise unobservable sentiment factors. Then, applying the Monte Carlo filter as a filtering method in a state space Bayesian filtering approach, we estimate the dynamic stochastic structure of these latent factors from observable variables driven by these latent variables. As a result, the three-factor model with text mining is able to distinguish (1) a spread-steepening factor which is driven by pessimists' view and explaining the spreads related to ultra-long term yields from (2) a spread- attening factor which is driven by optimists' view and in uencing the long and medium term spreads. Also, the three-factor model with text mining has better fitting to the observed yields than the model without text mining. Moreover, we collect market participants' views about specific spreads in the term structure and find that the movement of the identified sentiment factors are consistent with the market participants' views, and thus market sentiment.