1. Risk and uncertainty in Forest Investment: Risk management, decision making with uncertainty
Concept
Terminology
Difference between risk and uncertainty
Sources
Rational decisions and criterion
Mean expected value

2. Future is always uncertain: Farmers – few months to harvest crop
Industrial investors – a return within few years
But forester’s effort materialize (may not) after decades – even centuries
The uncontrollable and unpredictable factors operating over a forest rotation presents so horrifying a prospect that many foresters ignore them altogether. But this is inexcusable and irresponsible. There are techniques that help to predict the trend of relevant economic and political variables.

3. Terminology
State of nature: condition of factor in natural, economic or political environment over which the decision makers have no control e.g., rainfall, world timber price, drought
Strategy: course of action controlled by decision makers and adopted in response to risk and uncertainty e.g., planting a species tolerant to prolonged drought, fire insurance, doing nothing
Outcome: predicted result of a strategy in a given state of nature: if we plant pinus caribaea (strategy) and there is a prolonged drought (state of nature), the crop will fail (outcome).

4. Ignorance: we know nothing
Uncertainty: range of relevant states of nature, and therefore what outcomes are possible, but not the relative probabilities of each state of nature
Risk: distinguished from uncertainty by knowledge of the probability of each state of nature (tossing a coin)

5. Risk and uncertainty
Treating future circumstances as risky rather than uncertain needs either:
Actuarial data (historical evidence) – fire incidence, earthquake insurance
Mathematical modeling – forecasts
Certainty: which state of nature will eventuate, and precisely what outcome of strategy followed.

6. Sources of risks and uncertainties faced by forestry
Natural environment – climate hazards, biotic – insects, pathogens, browsing animals
Technological – new inventions (samill in Chaubas)
Human factors – accidental fires, illicit felling, encroachment
Market – unexpected surges and collapses (e.g., taxus)
Political milieu – changes of government, wars, policy and taxation

7. Rational decisions under uncertainty
A decision to establish plantations with associated sawmill in one of the three islands lying along a hurricane track.
Data for decision making under uncertainty (NPV $ million)
State Strategy
of nature St Fitts St Starts Ambigua
With hurricane
Without hurricane

8. Decision making criterion
Wald’s (1950): adopt strategy giving best outcome in worst circumstances – pessimistic
Maximax: select strategy of best outcome in the best state of nature - optimistic
Savage’s (1951): minimax regret is complex – devise the strategy for which maximum regret that could be felt is smaller than for any other strategy.

9. Savage contd
Should there be a hurricane, and st Fitts had been chosen, there will be no regret about the choice of strategy, but without hurricane, the NPV would be $ 8 million rather than $16 million which could have been obtained, had st starts been selected. The margin between what was actually obtained and what have been obtained in that state of nature is a measure of regret: in this case $8million.

10. The Minimax regret criterion
strategy
St Fitts St Starts Ambigua 3
With hurricane 7 6
Without hurricane 8

11. Which criterion? Wald’s – St Fitts Minimax – St Starts
Savage’s – Ambigua
The criteria gives 3 answers but none of the criteria takes account of the existing evidence on real frequency of hurricanes

12. RISK AND MEAN EXPECTED VALUE
Steps:
1) Classify strategies and state of nature
2) Determine the probability of each sate of nature from records, system simulation, expert’s and local people’s view, informed guesswork
3) Determine the outcome of each strategy under each state of nature
4) For each strategy, sum all the state of nature
5) This sum is the mean expected value of the strategy, the strategy with highest sum is selected.

13. Mean Expected Value

14. Effect of adding 5% risk premium to discount rate

15. Often revenues do become less certain the further into future that revenues accrue but:
1) not all risks increase over time (fire risk at early stage of plantation)
2) where risk do increase through time, it is not always in the exponential way of compound interest
3) Market and political uncertainty is not sufficient reason for discounting
4) a higher discount rate need not penalize investment at all, a risk premium of 5% actually makes the project acceptable.

16. Climate and market risk