How to deal with missing observations in surveys of professional forecasters

Survey forecasts are prone to entry and exit of forecasters as well not contributing every period leading gaps. These gaps make it difficult compare individual each other raises the question how deal with missing observations. This is addressed for variables GDP, CPI inflation, unemployment US. The theoretically optimal method filling in observations derived compared several competing methods. It found that taking previous value do perform particularly well. For methods assessed, there no clear superior approach all use cases, but one usually performs quite