activity
20192025
collaborators

5 papers

econ.GN2025

Killed in and after Action: The Long-lasting Effects of Combat Exposure on Mortality

Helmut Farbmacher, Rebecca Groh

This study examines long-term mortality effects of combat exposure using the Vietnam War draft lottery as a quasi-experiment. We validate the lottery by analyzing combat fatalities…

econ.EM2024

Revisiting the Many Instruments Problem using Random Matrix Theory

Helmut Farbmacher, Rebecca Groh, Michael Mühlegger +1

Instrumental variables estimation with many instruments is biased. Traditional bias-adjustments are closely connected to the Silverstein equation. Based on the theory of random mat…

econ.EM2022

Detecting Grouped Local Average Treatment Effects and Selecting True Instruments

Nicolas Apfel, Helmut Farbmacher, Rebecca Groh +2

Under an endogenous binary treatment with heterogeneous effects and multiple instruments, we propose a two-step procedure for identifying complier groups with identical local avera…

econ.EM2020

Causal mediation analysis with double machine learning

Helmut Farbmacher, Martin Huber, Lukáš Lafférs +2

This paper combines causal mediation analysis with double machine learning to control for observed confounders in a data-driven way under a selection-on-observables assumption in a…

econ.EM2019

On the Effect of Imputation on the 2SLS Variance

Helmut Farbmacher, Alexander Kann

Endogeneity and missing data are common issues in empirical research. We investigate how both jointly affect inference on causal parameters. Conventional methods to estimate the va…