Large business enterprises, from the railroad barons of nineteenth century America to Amazon and Google today, are often perceived as important for economic development and, at the same time, as potential threats to competition and even democracy. In this study, we compare the experiences of four countries that implemented policies to curb the influence of one type of large corporate entities – pyramidal business groups: The US in the 1930s; Japan during the American occupation (1945–1952); Korea following the Asian crisis (late 1990s); and Israel in the last decade (2010–2019). Novel regulatory measures, applied consistently in the US and Japan, where the extreme political circumstances were very favorable to economic reform, led to the demise of pyramidal business groups in these countries. Israel, where the reforms did not follow a severe crisis, also used specifically-designed regulatory tools over a decade-long period, resulting in a significant decline in the number and size of business groups. Korea, after experimenting with variety of regulatory measures, chose to rely primarily on corporate governance-focused reforms to curb the influence of the chaebol, but with limited effects; groups continue to dominate the Korean economy. Our findings point to the importance of specificallydesigned regulatory tools, applied consistently over time, against the backdrop of a pro-reform political climate.