Dynamics and Competition in Charitable Giving

Nowadays potential donors receive many direct mailings from many different charities, all soliciting their donations. As charities depend for a large part on their revenues from direct mail it is important to uncover the precise effects of charitable direct mailings on donating behavior. Existing studies on donating behavior generally focus on a single decision context, that is, a single donation to a single charitable cause. In reality, however, people receive many donation requests, and the responses to these requests may not be independent. In this thesis we study the dynamic and competitive effects of charitable direct mailings on donating behavior. We present two direct mailing response models, with the first focusing primarily on the competitive dimension, and the second focusing mainly on the dynamic dimension. To calibrate these models we have access to a unique dataset consisting of the databases of multiple charity organizations, providing us wi

Do Charities Get More when They Ask More Often? Evidence from a Unique Field Experiment

Charitable organizations send out large volumes of direct mailings, soliciting for money in support of many good causes. Without any request, donations are rarely made, and it is well known that each request for money by a charity likely generates at least some revenues. Whether a single request from a charity increases the total amount donated by an individual is however unknown. Indeed, a response to one request can hurt responses to others. The net effect is therefore not easily observable, certainly not when multiple charities address the same individuals. In this paper we alleviate these observational difficulties by carrying out a field experiment in which five large charities cooperate. With the unique data that we collect, we study the impact of sending more requests on total donations. The results indicate that there is a negative competitive effect on requests from other charities, but this effect dies out rapidly. Soon after the mailing has been sent, it is only a strong cannibalization of the charity’s own revenues that prevails. This empirical finding suggests the important conclusion that not much coordination across charities is needed to increase revenues. We also demonstrate that charities need sophisticated evaluation tools that do not ignore the effects of cannibalization

Does Irritation Induced by Charitable Direct Mailings Reduce Donations?

Charities mainly rely on direct mailings to attract the attention of potential donators. Individuals may feel irritated by these mailings, in particular when they receive many mailings. We study the consequences of perceived irritation on stated behavior and on actual behavior. Target selection by charities likely results in good donators receiving many mailings and hence they might also be most irritated. Therefore, irritation with direct mailings might be endogenously determined. To create exogenous variation in irritation, we design a unique controlled field experiment in cooperation with five of the largest charities in the Netherlands. Our analysis reveals that direct mailings do result in irritation, but surprisingly this affects neither stated nor actual donating behavior

Risk of postoperative acute kidney injury in patients undergoing orthopaedic surgery—development and validation of a risk score and effect of acute kidney injury on survival:observational cohort study

Funding: This study was funded by Tenovus Tayside, Chief Scientist Office, Scotland and a travelling fellowship from the Royal College of Physicians and Surgeons of Glasgow. The funders had no role in the study design; collection, analysis, and interpretation of the data; writing of the report; or the decision to submit the article for publication. The researchers are independent of the funders.Non peer reviewedPublisher PD

Predicting mortality after start of long-term dialysis-International validation of one- and two-year prediction models

BackgroundMortality prediction is critical on long-term kidney replacement therapy (KRT), both for individual treatment decisions and resource planning. Many mortality prediction models already exist, but as a major shortcoming most of them have only been validated internally. This leaves reliability and usefulness of these models in other KRT populations, especially foreign, unknown. Previously two models were constructed for one- and two-year mortality prediction of Finnish patients starting long-term dialysis. These models are here internationally validated in KRT populations of the Dutch NECOSAD Study and the UK Renal Registry (UKRR). MethodsWe validated the models externally on 2051 NECOSAD patients and on two UKRR patient cohorts (5328 and 45493 patients). We performed multiple imputation for missing data, used c-statistic (AUC) to assess discrimination, and evaluated calibration by plotting average estimated probability of death against observed risk of death. ResultsBoth prediction models performed well in the NECOSAD population (AUC 0.79 for the one-year model and 0.78 for the two-year model). In the UKRR populations, performance was slightly weaker (AUCs: 0.73 and 0.74). These are to be compared to the earlier external validation in a Finnish cohort (AUCs: 0.77 and 0.74). In all tested populations, our models performed better for PD than HD patients. Level of death risk (i.e., calibration) was well estimated by the one-year model in all cohorts but was somewhat overestimated by the two-year model. ConclusionsOur prediction models showed good performance not only in the Finnish but in foreign KRT populations as well. Compared to the other existing models, the current models have equal or better performance and fewer variables, thus increasing models' usability. The models are easily accessible on the web. These results encourage implementing the models into clinical decision-making widely among European KRT populations.Peer reviewe

Meer betaalgemak door de euro.

De euro geeft meer betaalgemak dan de gulden. Empirisch onderzoek laat zien dat Nederlanders efficiënter dan in het guldentijdperk betalen met de reeks van eurobiljetten en -munten. Ook heeft men - in tegenstelling tot de gulden - geen sterke voorkeur voor bepaalde coupures

Prediction meets causal inference: the role of treatment in clinical prediction models

In this paper we study approaches for dealing with treatment when developing a clinical prediction model. Analogous to the estimand framework recently proposed by the European Medicines Agency for clinical trials, we propose a ‘predictimand’ framework of different questions that may be of interest when predicting risk in relation to treatment started after baseline. We provide a formal definition of the estimands matching these questions, give examples of settings in which each is useful and discuss appropriate estimators including their assumptions. We illustrate the impact of the predictimand choice in a dataset of patients with end-stage kidney disease. We argue that clearly defining the estimand is equally important in prediction research as in causal inference