  One of the long-term goals of exoplanet science is the (atmospheric)
characterization of a large sample (>100) of terrestrial planets to assess
their potential habitability and overall diversity. Hence, it is crucial to
quantitatively evaluate and compare the scientific return of various mission
concepts. Here we discuss the exoplanet yield of a space-based mid-infrared
(MIR) nulling interferometer. We use Monte-Carlo simulations, based on the
observed planet population statistics from the Kepler mission, to quantify the
number and properties of detectable exoplanets (incl. potentially habitable
planets) and we compare the results to those for a large aperture optical/NIR
space telescope. We investigate how changes in the underlying technical
assumptions (sensitivity and spatial resolution) impact the results and discuss
scientific aspects that influence the choice for the wavelength coverage and
spectral resolution. Finally, we discuss the advantages of detecting exoplanets
at MIR wavelengths, summarize the current status of some key technologies, and
describe what is needed in terms of further technology development to pave the
road for a space-based MIR nulling interferometer for exoplanet science.
