Specific language impairment (SLI) is diagnosed when a child's language does not develop normally and the difficulties cannot be accounted for by generally slow development, physical abnormality of the speech apparatus, autism spectrum disorder, acquired brain damage or hearing loss.
Perfect competition. A perfectly competitive market is a hypothetical market where competition is at its greatest possible level. Neo-classical economists argued that perfect competition would produce the best possible outcomes for consumers, and society.
Consumers perceive that there are non-price differences among the competitors' products. There are few barriers to entry and exit. Producers have a degree of control over price. The long-run characteristics of a monopolistically competitive market are almost the same as a perfectly competitive market.