Impact of rent taxation on Norwegian salmon farming companies

This paper investigates the impact of the rent tax announcement and implementation in Norway in sea-based salmonid aquaculture on stock returns of affected companies. Our sample period ranges from August 2, 2022 to February 1, 2023, covering both the announcement and implementation day. By applying a difference-in-differences approach, we measure the causal effect that the rent tax had on the returns of the affected companies (companies that operate in Norway) relative to the non-affected companies (those that operate outside of Norway). Our findings reveal a statistically significant, large negative return in the affected companies on the announcement day. Return on implementation day was close to zero. This result is consistent with the efficient market hypothesis, where only new information should move stock prices.