20
Comparing this with equation [17] shows that, as opposed to Proposition 3’ denying
access to private forest affects the adjustment of public rotation age compared with
Proposition 5. More specifically, we have
Proposition 5’. If the relationship between the private and public forest stands is
temporally interdependent (FτT > (<) 0), denying access to private forests will
shift the optimal private rotation age towards that of temporally independent
stands from above, if FTg > (<)0, or below, if FTg < (>)0 .
As Proposition 5’ indicates, again the size of the externality is decreased such that the
rotation age becomes closer to that of independent stands.
The analysis of public harvesting as a two-stage game with the Forest Service being a
Stackelberg leader gives a set of harvesting rules that differ substantially from those
usually given in forest economics. The socially optimal harvesting rules depend on i)
whether recreators have free access private forests or not, ii) how amenity valuation
changes with the age of forest stands, and iii) how the degree of complementarity or
substitutability between public and private forests in the valuation of amenity services
evolves over time. The first aspect is institutional and varies from country to country,
while the other two are basically empirical questions, and are interesting areas for
research.
4. Conclusions
We have re-examined the literature of interdependent stands in the Hartman model,
and applied our analysis to the determination of public rotation age. Our analysis
contributes the existing literature in several ways. First, we have clarified the potential
interdependence between two adjacent stands and offered a new interpretation of the
concepts of spatial and temporal interdependence. While spatial interdependence
means complementarity/substitutability between the stands, temporal interdependence
means that the degree of substitutability/complementarity between stands, may
increase, decrease or remain constant with the age of the stands. Second, we have
shown that the comparative statics of private rotation age is not always conventional.