  We discuss the impact of a Covid-19--like shock on a simple model economy,
described by the previously developed Mark-0 Agent-Based Model. We consider a
mixed supply and demand shock, and show that depending on the shock parameters
(amplitude and duration), our model economy can display V-shaped, U-shaped or
W-shaped recoveries, and even an L-shaped output curve with permanent output
loss. This is due to the economy getting trapped in a self-sustained "bad"
state. We then discuss two policies that attempt to moderate the impact of the
shock: giving easy credit to firms, and the so-called helicopter money, i.e.
injecting new money into the households savings. We find that both policies are
effective if strong enough. We highlight the potential danger of terminating
these policies too early, although inflation is substantially increased by lax
access to credit. Finally, we consider the impact of a second lockdown. While
we only discuss a limited number of scenarios, our model is flexible and
versatile enough to accommodate a wide variety of situations, thus serving as a
useful exploratory tool for a qualitative, scenario-based understanding of
post-Covid recovery. The corresponding code is available on-line.
