brackets equation latex
documentclass{article}
usepackage{amsmath}
begin{document}
begin{equation}
D_{it} =
begin{cases}
1 & text{if bank $i$ issues ABs at time $t$}\
2 & text{if bank $i$ issues CBs at time $t$}\
0 & text{otherwise}
end{cases}
end{equation}
end{document}