The announcement effect is the immediate change in prices or behavior that occurs when new information becomes public, even before the announced action actually happens. Economically, the point is that markets and decision-makers respond to expected future conditions, not only to events that have already occurred.
Why It Happens
If households, firms, and investors are forward-looking, then credible news changes their expectations right away. A central bank statement can move bond yields immediately. A future tax change can shift spending into the present. An earnings announcement can reprice a company’s stock before anything physical changes inside the firm.
Expectations And Credibility
The size of the announcement effect depends heavily on credibility. If market participants do not believe the announcement will be followed through, the reaction is usually smaller. That is why institutional reputation, communication quality, and policy consistency matter.
Policy And Market Examples
Common cases include:
- monetary-policy guidance moving interest rates and exchange rates
- fiscal announcements shifting consumption or investment timing
- corporate earnings news moving equity prices
- regulatory or trade announcements changing inventories, supply chains, or valuations
Knowledge Check
### What is the announcement effect?
- [x] Prices or decisions changing today because new information changes expectations about the future
- [ ] Prices changing only after a policy is fully implemented
- [ ] A ban on public communication by firms and governments
- [ ] A bookkeeping rule for delayed expenses
> **Explanation:** The core idea is that forward-looking agents react when the news arrives, not only when the underlying event occurs.
### Why is credibility important for the announcement effect?
- [ ] Because announcements work even if nobody believes them
- [x] Because the reaction is stronger when people expect the promised future action to occur
- [ ] Because only false announcements move markets
- [ ] Because credibility matters only in labor markets
> **Explanation:** Expectations change most when the announcement is viewed as believable and actionable.
### Which is a standard example of an announcement effect?
- [ ] Factory output falling after a broken machine
- [x] Bond yields moving immediately after a central bank signals a future rate path
- [ ] GDP changing only after historical revisions are published years later
- [ ] Wages changing only after annual tax filing
> **Explanation:** Financial prices often adjust immediately when new policy information changes expected future cash flows or discount rates.