I found it interesting to look at correlations between excess mortality from all causes, as reported by EuroMOMO for Week 16 of this year, and the quarantine stringency indices calculated by this project https://www.bsg.ox.ac.uk/research/research-projects/coronavirus-government-response-tracker for three dates: March 1, March 15 and April 1.

The correlations are week but the intuitions behind them (in further tweets on this thread) make sense, I think. (DISCLAIMER: I am not an academic, I only run the numbers for my own understanding of what's going on).

For March 1, the correlation is positive. That's understandable: At that point, only countries where governments saw the most worrying data introduced relatively strict quarantine measures.

For March 15, the correlation is the strongest of the three and negative. The intuition there is that quarantines did help "smooth the curve" and drive down excess mortality, even if the relationship between stringency and mortality is not very strong.