The notion of microfoundations has received growinginterest in neo-institutional theory (NIT) along with an increasing interest inmicrofoundational research in disciplines such as strategic management andorganizational economics. However, despite reference to the same term, thereare decisive differences in how microfoundations have been addressed acrossdifferent disciplines.The aim of this double volume is to explore in moredepth what the microfoundations of institutions are and what it takes toactually develop sound microfoundations. To this end, this double volume setsoff by exploring the recent well-spring of micro-level research in NIT (i.e.,research on the individual, practice and group level). While intimatelyrelated, micro-level research and microfoundations are not necessarily the samething. Hence, the double volume seeks to bring to the fore differentperspectives in micro-level research in order to tease out what theseperspectives imply for building microfoundations, where they converge and wherethey diverge.