What works to increase charitable donations? A meta-review with meta-meta-analysis

Many charities rely on donations to support their work addressing some of the world’s most pressing problems. We conducted a meta-review to determine what interventions work to increase charitable donations. We found 21 systematic reviews incorporating 1339 primary studies and over 2,139,938 participants. Our meta-meta-analysis estimated the average effect of an intervention on charitable donation size and incidence: r = 0.08 (95% CI [0.03, 0.12]). Due to limitations in the included systematic reviews, we are not certain this estimate reflects the true overall effect size. The most robust evidence found suggests charities could increase donations by (1) emphasising individual beneficiaries, (2) increasing the visibility of donations, (3) describing the impact of the donation, and (4) enacting or promoting tax-deductibility of the charity. We make recommendations for improving primary research and reviews about charitable donations, and how to apply the meta-review findings to increase charitable donations

Interventions that Influence Animal-Product Consumption: A Meta-Review

Transitioning toward plant-based diets can alleviate health and sustainability challenges. However, research on interventions that influence animal-product consumption remains fragmented and inaccessible to researchers and practitioners. We conducted an overview of systematic reviews, also known as a meta-review. We searched five databases for reviews that examined interventions that influence (increase or decrease) the consumption of animal products. We quantitatively summarised results using individual studies’ directions of effect because reviews rarely reported effect sizes of primary studies. Eighteen reviews met inclusion criteria, 12 of which examined interventions intended to decrease animal-product consumption and 6 of which examined interventions intended to increase animal-product consumption. In total, only two reviews conducted quantitative meta-analyses. Across all reviews, vote counting indicated that providing information on the environmental impact of meat consumption may reduce consumption, with 10 of 11 estimates suggesting reduced consumption (91%, 95% CI [62.3%, 98.4%]; p = .012). Providing information on the health consequences, emphasising social norms, and reducing meat portion sizes also appeared promising, albeit with more limited evidence. Reviews examining interventions that decreased consumption predominately focused on meat (10/12 reviews). Future reviews should conduct quantitative syntheses where appropriate and examine interventions that influence the consumption of animal products other than meat