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Research

Papers, doctoral research, conferences, and seminars.

Papers 3

012025
Job market paperRead paper ↗

When Is News Really News? Evidence from Cryptocurrency Markets

Ulrich D. S. AIOUNOU

NLPSentiment analysisCryptocurrencyNews sentimentForecasting
AbstractShowHide

This chapter examines whether news sentiment provides additional predictive information for cryptocurrency returns and volatility beyond that contained in market variables. I use asset-specific news headlines collected from GDELT to construct two daily sentiment measures based on a financial lexicon and FinBERT.The analysis covers Bitcoin, Ether, Solana, and XRP, with multipleforecast horizons. Seven forecasting models are considered, including linearregressions, tree-based methods, and a neural network.Forecasting performance is evaluated using an expanding-windowapproach, with RMSE comparisons and the Clark-West test.I consider both a common sample and asset-native samplesto examine the sensitivity of the results to the sampledesign. The analysis also examines whether the predictivecontribution of sentiment differs between high- andlow-volatility market conditions. The results indicate that news sentiment provides morefavorable improvements for volatility forecasting thanfor returns. Statistically supported return gains arerelatively limited and rarely persist across the twosample designs. In contrast, several volatility forecastsbenefit from sentiment information, with the largestimprovements generally obtained using Multilayer Perceptron(MLP), particularly for XRP. However, some of these gainsweaken or reverse when different sample periods areconsidered. The results also show that improvements occurunder different market volatility conditions, without a consistent advantage for either regime.

022024
Work in progress

A regime switching Gegenbauer model of unemployment rates in the G7 countries

Ulrich D. S. AIOUNOU · Gilles Dufrénot

Gegenbauer processRegime switchingSTAR modelhysteresislong memoryUnemployment rates
AbstractShowHide

We propose a regime-switching smooth transition autoregressive model built on a two-factor Gegenbauer process (RSG-STAR) to study unemployment dynamics in the G7 countries. The framework jointly captures long memory at cyclical frequencies, anti-persistent volatility, and asymmetric state-dependent adjustment. A feasible alternating nonlinear least-squares estimator and a dedicated linearity test are developed. The linearity test rejects a linear Gegenbauer null at the 1% level for all seven countries, with the rejection reflecting both STAR nonlinearity and inadequacy of the linear memory specification. Generalised impulse response functions show that regime switching amplifies long-memory persistence in Canada and France, moderates it in Germany and Japan, and produces explosive trajectories in the United Kingdom and the United States, with direct implications for the design of stabilisation policy.

032023
Working paperRead paper ↗

Estimation in high-dimensional linear regression: Post-Double-Autometrics as an alternative to Post-Double-Lasso

Ulrich D. S. AIOUNOU · Sullivan Hué · Sébastien Laurent · Emmanuel Flachaire

High-dimensionalTreatment effectLassoAutometricsOmitted variable bias
AbstractShowHide

Post-Double-Lasso is becoming the most popular method for estimating linear regression models with many covariates when the purpose is to obtain an accurate estimate of a parameter of interest, such as an average treatment effect. However, this method can suffer from substantial omitted variable bias in finite sample. We propose a new method called Post-Double-Autometrics, which is based on Autometrics, and show that this method outperforms Post-Double-Lasso. Its use in a standard application of economic growth sheds new light on the hypothesis of convergence from poor to rich economies.

Doctoral research

Doctoral thesis

Essays in Modern Econometrics: Variable Selection, Time Series and Machine Learning

Variable selection, causal inference, long memory, and forecasting: my research connects modern econometric methods with economic applications.

Machine learning & Variable selection in High dimensionAdvanced econometricsTime Series, Long memory and Spectral analysisNLP and Forecasting

Research exchanges

Research visits02

  1. —

    Laval University

    Hosted by Marie-Hélène Gagnon

    Research visit

  2. Concordia University

    Hosted by Prosper Dovonon

    Research visit

Talks & conferences 8

Dates, events, institutions, and locations.

8 / 8 presentation(s)

  1. 2026

    1. Date

      Event

      Economics Seminar

      Institution: Concordia University

      Seminar

      Location

      Montreal, Canada

    2. Date

      Event

      CRREP Research Day

      Conference / workshop

      Location

      Quebec City, Canada

  2. 2025

    1. Date

      Event

      PhD Seminar

      Institution: CREST

      Seminar

      Location

      Palaiseau, France

  3. 2024

    1. Date

      Event

      CFE-CMStatistics 2024

      Conference / workshop

      Location

      London, UK

    2. Date

      Event

      Doctoral Workshop on Applied Econometrics

      Conference / workshop

      Location

      Konstanz, Germany

    3. Date

      Event

      Franco-Japanese Webinar

      Institution: Aix-Marseille University

      Seminar

      Location

      Online

  4. 2023

    1. Date

      Event

      Franco-Japanese One-Day Seminar on International Economics and Finance

      Institution: Aix-Marseille University

      Seminar

      Location

      Aix-en-Provence, France

  5. 2022–2026

    1. Date

      Seminar series

      Event

      PhD Seminar

      Institution: Aix-Marseille University

      Seminar

      Location

      Marseille, France

Collaborations

Econometrics, machine learning, and reproducible research.

I’m open to research collaborations. Feel free to reach out.

Get in touch ↗