We assess absolute magnitudes, relative importance and inter-temporal differences in firm, industry and business group effects in explaining the variance of Indian manufacturing firms’ profitability, over the twenty-six year period between 1980-81 and 2005-06. We stratify the data by institutional phases to place emphasis on the role of changing institutional factors in an emerging economy, as a regime of command and control transits to partial liberalization, between 1985 and 1991, to an open competitive market economy after 1991; thereafter financial reforms occur, followed by the occurrence of legal reforms. We find that liberalization significantly affects and alters the relative importance of firm, industry and group effects. Firm effects are always important, whether in a command and control regime, with benefits accruing from protectionism and political rent seeking, or in liberalized periods where firm specific capabilities and dynamic efficiencies are valued. Industry effects are significant in the command and control regime, when mandatory sector placement benefited firms in industries with superior profits, and in the liberalized period, when the choice of the industry segment to operate in is open to firms. Thereafter, industry effects dissipate. Business group effects matter in explaining profitability variances. Group effects magnitudes, however, do not change significantly over time.