Professor Kyle Bagwell har skrivit en imponerande översiktsartikel om reklam, ”The Economic Analysis of Advertising”, publicerad i Handbook of Industrial Organization. Om reklamens effekter på pris finner forskningen:

In summary, the impact of manufacturer advertising on retail prices is complex. There is some evidence, though, that manufacturer advertising may encourage loss-leaders featuring the advertised item and facilitate the growth of low-price discount outlets. For many industries, there is also substantial evidence that retail advertising leads to lower retail prices.

När det gäller effekter på kvalitet finner forskningen:

[T]he studies described here do not offer strong support for the hypothesis of a systematic positive relationship between advertising and product quality. The studies do suggest, however, that a positive relationship is more likely when advertising conveys direct information (broadly defined) to consumers. Finally, when advertising is allowed in retail service industries, there is some evidence that advertising firms may have lower product quality and non-advertising firms may have higher product quality than they would were advertising not allowed.

Reklam verkar alltså ha blandade effekter. Värderar man låga priser verkar reklam kunna fylla en i huvudsak positiv funktion, men kanske till priset av lägre kvalitet på de varor som annonseras.