  The formation of massive stellar clusters is intricately linked to star
formation on local and global scales. All actively star forming galaxies are
forming clusters, and the local initial conditions likely determine whether
bound massive clusters or unbound associations are formed. Here, we focus on
observed scaling relations between cluster populations and the properties of
the host galaxy. In particular, we discuss the relations between the fraction
of U-band light from clusters vs. their host galaxy as well as the brightest
cluster vs. population size and host galaxy star formation rate (SFR). We also
discuss the the fraction of stellar mass formed within bound clusters within
the Galaxy, nearby dwarf galaxies, as well as starbursts and mergers. Bound
clusters appear to represent ~10% of star formation within most galaxies,
although there are intriguing hints that this fraction systematically increases
in galaxies with higher star formation rate surface densities. Throughout the
review we highlight potential avenues for future study.
