The Structure-Conduct-Performance (SCP) paradigm was the dominant framework for empirical research in industrial organization (IO) between 1950s and early 1980s. The paradigm postulates a causality chain running from market structure, ﬁrms’ conduct and their performance. By the 1980s, game theoretic theorizing became increasing popular in IO. The empirical counterpart of this research program is the New Empirical Industrial Organization (NEIO). Even though NEIO is today the preferred empirical approach in mainstream IO, the SCP paradigm continued to be used albeit to a lesser degree and often using improved econometric estimation techniques. Scholars have also attempted to synthesize elements in the SCP and those associated with stochastic market structure models based on the law of proportionate eﬀect (LPE). Despite and perhaps because of their formal sophistication and often demanding data requirement, the number of empirical studies based on the NEIO and variants of the LPE model have not approached the volume of empirical SCP studies during the three decades between 1950s to 1980s. This is particularly true for developing countries where the SCP paradigm continues to be inﬂuential. However, this may change in the future if the quality and availability of market-level data improves.