Université de Fribourg

Assessing the effects of seasonal tariff-rate quotas on vegetable prices in Switzerland

Loginova, Daria ; Portmann, Marco ; Huber, Martin

(Working Papers SES ; 521)

Causal estimation of the short-term effects of tariff-rate quotas (TRQs) on vegetable producer prices is hampered by the large variety and different growing seasons of vegetables and is therefore rarely performed. We quantify the effects of Swiss seasonal TRQs on domestic producer prices of a variety of vegetables based on a difference-indifferences estimation using a novel dataset of weekly...

Université de Fribourg

Direct and indirect effects under sample selection and outcome attrition

Huber, Martin ; Solovyeva, Anna

(Working Papers SES ; 496)

This paper considers the evaluation of direct and indirect treatment effects, also known as mediation analysis, when outcomes are only observed for a subpopulation due to sample selection or outcome attrition. For identification, we combine sequential conditional independence assumptions on the assignment of the treatment and the mediator, i.e. the variable through which the indirect effect...

Université de Fribourg

Nonparametric estimation of natural direct and indirect effects based on inverse probability weighting

Hsu, Yu-Chin ; Huber, Martin ; Lai, Tsung Chih

(Working Papers SES ; 482)

Using a sequential conditional independence assumption, this paper discusses fully nonparametric estimation of natural direct and indirect causal effects in causal mediation analysis based on inverse probability weighting. We propose estimators of the average indirect effect of a binary treatment, which operates through intermediate variables (or mediators) on the causal path between the...

Université de Fribourg

The finite sample performance of inference methods for propensity score matching and weighting estimators

Bodory, Hugo ; Huber, Martin ; Camponovo, Lorenzo ; Lechner, Michael

(Working Papers SES ; 466)

This paper investigates the finite sample properties of a range of inference methods for propensity score-based matching and weighting estimators frequently applied to evaluate the average treatment effect on the treated. We analyse both asymptotic approximations and bootstrap methods for computing variances and confidence intervals in our simulation design, which is based on large scale labor...