(Working Papers SES ; 513)
We propose a new method for flagging bid rigging, which is particularly useful for detecting incomplete bid-rigging cartels. Our approach combines screens, i.e. statistics derived from the distribution of bids in a tender, with machine learning to predict the probability of collusion. As a methodological innovation, we calculate such screens for all possible subgroups of three or four bids...
|
(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...
|
(Working Papers SES ; 456)
This paper evaluates the effect of a voucher award system for assignment into vocational training on the employment outcomes of unemployed voucher recipients in Germany, along with the causal mechanisms through which it operates. It assesses the direct effect of voucher assignment net of actual redemption, which may be driven by preference shaping/learning about (possibilities of) human capital...
|
(Working Papers SES ; 472)
This study empirically evaluates the impact of the war in eastern Ukraine on the political attitudes and sentiments towards Ukraine and Russia among the population living close to the war zone on the territory controlled by the Ukrainian government. Exploiting unique survey data that were collected in early 2013 (13 months before the outbreak of the conflict) and early 2015 (11 months after the...
|
(Working Papers SES ; 500)
Mediation analysis aims at evaluating the causal mechanisms through which a treatment or intervention affects an outcome of interest. The goal is to disentangle the total treatment effect into an indirect effect operating through one or several observed intermediate variables, the so-called mediators, as well as a direct effect reflecting any impact not captured by the observed mediator(s)....
|
(Working Papers SES ; 470)
We introduce a wild bootstrap algorithm for the approximation of the sampling distribution of pair or one-to-many propensity score matching estimators. Unlike the conventional iid bootstrap, the proposed wild bootstrap approach does not construct bootstrap samples by randomly resampling from the observations with uniform weights. Instead, it fixes the covariates and constructs the bootstrap...
|
(Working Papers SES ; 469)
This paper investigates the effects of an information campaign about a governmental rural development program (RDP) in the Former Yugoslav Republic of Macedonia on the farmers’ intention to participate in the RDP. In the course of a survey among farmers, the treatment group received an information brochure with relevant details on selected RDP measures, while the control group received no...
|
(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...
|
(Working Papers SES ; 481)
This paper suggests a causal framework for disentangling individual level treatment effects and interference effects, i.e., general equilibrium, spillover, or interaction effects related to treatment distribution. Thus, the framework allows for a relaxation of the Stable Unit Treatment Value Assumption (SUTVA), which assumes away any form of treatment-dependent interference between study...
|
(Working Papers SES ; 479)
This paper provides a review of methodological advancements in the evaluation of heterogeneous treatment effect models based on instrumental variable (IV) methods. We focus on models that achieve identification through a monotonicity assumption on the selection equation and analyze local average and quantile treatment effects for the subpopulation of compliers. We start with a comprehensive...
|
