There are now enough cases in Europe to get a faint idea of local transmission dynamics. Of the 11 known cases so far in Germany, only one has transmitted the virus. Israel has 4 cases, with one local transmission attributable to them. Portugal has 13 cases, with 12 of those being local transmission all attributable to the same index case.
If we can collect similar information from other countries, we could get reasonable estimates of R_eff.
Source for Germany: https://docs.google.com/spreadsheets/u/0/d/1BA2GoeVMhC_dCcnl5qtR-fxpCwVH6xu8T3LxHUss1Gw/htmlview
For the sake of correctness/completeness: The chemical compound purchase was not done by ARC, but by another unspecified red-team.