It is said and insisted that it is necessary, but the most important question is whether it is truly Law.
An approach to competition law that seeks the existence of a competition authority that allows actions is undoubtedly a constitutional aberration.
An authorization to sell my business is essentially an indirect expropriation. The justification that selling my business to X person will cause harm to a “competition in the market” is also fallacious because it is not possible to predict the actual outcome of that transaction. It should be possible for me to sell my business without restrictions, let alone with prior authorization.
The justification that a market transaction will have a negative effect or, for the purposes of this discussion, any effect, is at least arrogant. A concentration, as they call it, may imply a temporary monopoly, however, it has already been accepted that monopolies are not inherently bad. It may also be the case that this concentration allows a combination of skills that significantly improves an industry and gives rise to a renewed business niche. It is unpredictable.
Giving the power to an authority to decide in advance what is good or bad implies their ability to predict the future. With one more effect: since they can prohibit a transaction, it may never occur, and they will have no responsibility, given the impossibility of demonstrating that such a transaction would have been positive and would have generated benefits, nor will it be possible to prove that the prohibition caused damages and their amount, as that future is unpredictable and never happened.
Government acts must have consequences for officials. Private acts, obviously, as well. However, a system of prior authorization makes it practically impossible to ascertain these responsibilities in officials and quantify the amounts of damages caused.
In economic matters, although less intrusive and less arbitrary, it is not even possible to sanction a concentration or segregation of businesses afterwards, as the real economic effects can be positive in the medium term when economic agents and suppliers adjust to a new set of economic actors.
For example, in 1970, it was impossible to imagine that IBM would no longer be dominant in the computer market.