TY  - JOUR
A1  - Caliendo, Marco
A1  - Clement, Michel
A1  - Papies, Dominik
A1  - Scheel-Kopeinig, Sabine
T1  - The cost impact of spam filters measuring the effect of information system technologies in organizations
JF  - Information systems research
N2  - Dealing with spam is very costly, and many organizations have tried to reduce spam-related costs by installing spam filters. Relying on modern econometric methods to reduce the selection bias of installing a spam filter, we use a unique data setting implemented at a German university to measure the costs associated with spam and the costs savings of spam filters. Our methodological framework accounts for effect heterogeneity and can be easily used to estimate the effect of other IS technologies implemented in organizations.
 The majority of costs stem from the time that employees spend identifying and deleting spam, amounting to an average of approximately five minutes per employee per day. Our analysis, which accounts for selection bias, finds that the installation of a spam filter reduces these costs by roughly one third. Failing to account for the selection bias would lead to a result that suggests that installing a spam filter does not reduce working time losses.
 However, cost savings only occur when the spam burden is high, indicating that spam filters do not necessarily reduce costs and are therefore no universal remedy. The analysis further shows that spam filters alone are a countermeasure against spam that exhibits only limited effectiveness because they only reduce costs by one third.
KW  - spam
KW  - spam filter
KW  - selection bias
KW  - propensity score matching
Y1  - 2012
U6  - https://doi.org/10.1287/isre.1110.0396
SN  - 1047-7047
VL  - 23
IS  - 3
SP  - 1068
EP  - 1080
PB  - INFORMS
CY  - Hannover
ER  - 
TY  - JOUR
A1  - Caliendo, Marco
A1  - Clement, Michel
A1  - Shehu, Edlira
T1  - The effect of individual professional critics on books' sales: capturing selection biases from observable and unobservable factors
JF  - Marketing letters : a journal of research in marketing
N2  - We propose a combined approach of propensity score matching with difference-in-differences methods for reducing selection biases of products being reviewed by critics. Critics' decision to review products may be driven by observable (e.g., star power) and unobservable (e.g., critics' individual preferences) factors, raising the question of reverse causality and selection biases. Our proposed approach enables to rigorously control for selection biases by observable and unobservable characteristics. We apply our methodological framework on data from the German book market and estimate the sales effect of a well-known TV critic. We identify substantial selection effects of individual critics, which result in serious underestimation of the short-term effect (up to 29 %) and the long-term effect (up to 37 %). The results emphasize the relevance of the proposed methodological framework by demonstrating that observable and unobservable factors drive selection effects.
KW  - Critics
KW  - Reviewer
KW  - Propensity score matching
KW  - Difference-in-difference
KW  - Selection effects
Y1  - 2015
U6  - https://doi.org/10.1007/s11002-015-9391-9
SN  - 0923-0645
SN  - 1573-059X
VL  - 26
IS  - 4
SP  - 423
EP  - 436
PB  - Springer
CY  - Dordrecht
ER  -