Now antitrust guidelines are similar throughout the developed world, and often local joint ventures of Western companies are still expected to comply with American or European competition law. Current practice usually requires that at least four companies be included in any comparison group, to avoid revealing any one company’s data points. The thinking behind this guideline is that any operating company will first extract their own data from the comparison set, leaving only three companies’ data, but it is difficult to break the data down further. In contrast, if only two or three companies are included in a
comparison data set, once the company’s own data are extracted the remaining data can be broken down to reveal exact data points of their competitors.