Brian conducts a study to examine the ability of boys and girls in solving difficult mathematical problems. he expects girls to perform much better than boys and communicates his expectation to the participants in a subtle manner. this is an example

Experimenter bias.

Explanation: Experimenter bias is the condition which describes a person as a part of experiment who is influencing the outcome of the experiment so that the desired or preferred results can be obtained.Experimenter bias is also known as research biasing.

The example mentioned in the question where Brian is conducting the study with sharing his views with the participants that he expects girls should perform better than boys in the experiment is example of experimenter bias.

The actual experiment should have been conducted without any thought sharing or acknowledgement which would have produced unbiased outcomes.But according to Brain's study, the expectations are conveyed ,therefore it will influence the result of the experiment as it becomes biased.

trade regulation is a field of law, often bracketed with antitrust (as in the phrase “antitrust and trade regulation law”), including government regulation of unfair methods of competition and unfair or deceptive business acts or practices. antitrust law is often considered a subset of trade regulation law. franchise and distribution law, consumer protection law, and advertising law are sometimes considered parts of trade regulation law.

in general the theory of economics says that the more open to trade a country is the better   the result for the same country and the whole economies.

in real life countries impose taxes, quotas, etc which is not so good for the economies.

this kind of commercial war between the usa and china is slowing down the growth of the whole world so we can say that it is a draw back of trade regulations. and the free trade agreements are benefits of trade regulations.

what words? are you talking about to complet what sentence