  We investigate the behavior of Boolean dimension with respect to components
and blocks. To put our results in context, we note that for Dushnik-Miller
dimension, we have that if $\dim(C)\le d$ for every component $C$ of a poset
$P$, then $\dim(P)\le \max\{2,d\}$; also if $\dim(B)\le d$ for every block $B$
of a poset $P$, then $\dim(P)\le d+2$. By way of constrast, local dimension is
well behaved with respect to components, but not for blocks: if
$\text{ldim}(C)\le d$ for every component $C$ of a poset $P$, then
$\text{ldim}(P)\le d+2$; however, for every $d\ge 4$, there exists a poset $P$
with $\text{ldim}(P)=d$ and $\dim(B)\le 3$ for every block $B$ of $P$. In this
paper we show that Boolean dimension behaves like Dushnik-Miller dimension with
respect to both components and blocks: if $\text{bdim}(C)\le d$ for every
component $C$ of $P$, then $\text{bdim}(P)\le 2+d+4\cdot2^d$; also if
$\text{bdim}(B)\le d$ for every block of $P$, then $\text{bdim}(P)\le
19+d+18\cdot 2^d$.
