I am currently completing my master's dissertation on private equity performance versus public stock markets.
I want to use a meta-analysis to study prior literature, on whether private equity outperforms in terms of investment return versus public stock markets. There are many papers on this topic, all with conflicting conclusions.
The Question I need Help with;
I am unsure of what effect sizes to use for the analysis. The papers generally give you a binary/dichotomous answer (yes/no - whether private equity outperforms stock markets). Problem with this I have noticed is that in previous examples there is a treatment and control group and with the papers I want to analyse, this does not exist.
Or the papers give a percentage value (e.g. Private equity outperforms by 3.79% per annum versus stock markets). Can the difference in percentage values given by the papers be used to calculate an effect size? I have not seen examples that use percentages to get effect sizes.
What effect size should I use? Are this values applicable to get effect sizes or should I try something else? Is this possible to calculate for a meta-analysis?
I look forward to any help anyone can provide! Thanks!