Overview of this part… Natural Resources theory: –Non-renewables –Renewables –Applied studies of theory – is it true? –Fisheries –Forestry Energy security – valuation issues Climate Change
Health warning This lecture contains a lot of maths. Later lectures wont be quite so bad (promise!!!) Key: understanding the concepts, not necessarily the maths Though if you can handle the maths this would be great.
Readings This lecture largely based on chapters 7,8,9 of HSW More advanced – see Conrad and Clark chapter 3 Other sources (go to if dont follow above): Perman et al
Definitions Non-renewables – eg coal Renewables – eg fish stocks or flows (eg wind)
Concepts you will need to have an idea of… Hamiltonian – specialised form of Lagrangian – see Perman or Pemberton and Rau if you dont understand this in this lecture. Market structures – monopoly, oligopoly, perfect competition – see basic micro text book to refresh if youve forgotten! Discounting – intertemporal issues. See Perman.
Hamiltonian ),,(],,,,,[tqxgtxqtxqH profit plus change in stock valued by shadow price. To maximise => 0 q H and x H These conditions and equation of motion (change in x) give a set of differential equations which define an optimal solution. (it also has to satisfy traversality conditions but we wont go into this– seeHSW ) Hamiltonian helps to solve the control problem. Similar to Lagrangian.
Discounting Social rate of time preference => reduce future values to reflect this. Usual notation: discount rate is r (occasionally i). 1/((1+r)^t) gives you the multiplier to reduce any value in time t to the current time. Eg 1/1.08 may give you the multiplier for t=1 and r=8% => £1 = £ Note r=8% does not lead to 0.92 in period t=1, because 1.08 in t=1 would be equal to 1 in t=0 (0.92 in t=0 does not equate to £1 in t=1 => try it!)
The basics If LHS is greater than RHS it pays to reduce extraction If LHS is less than RHS it pays to increase extraction But note, adjustment is inherently unstable!
The basics (2): No Substitute for the ER Resource is progressively exhausted on the price path. Eventually resource may be exhausted but this can take infinitely long!
The Basics (3): Backstop exists Resource is progressively exhausted on the price path. But now when price reaches Backstop Price the producer must have nothing left. For this to work initial price must be correct Lower is r, higher is initial price and lower is extraction initially
Extensions to model: Effect of Extraction Costs –Now net income (price minus extraction cost) must rise at rate of interest. –But if extraction costs fall, then initially extraction increases. Price time
Extensions to the Model (3) New Discoveries Effect is similar to an decrease in the price of the substitute – you extract faster. With unanticipated discoveries we see the following pattern:
Extensions to Basic Model (2) Capital Costs –These are part of extraction costs and are sensitive to interest rates. If r rises then extraction costs rise, resulting in slower extraction. But higher is r faster is extraction on Hotelling grounds. Technology Changes –If backstop price falls, extraction must increase. –If technology lowers extraction costs, extraction also increases initially.
Economic Approach to Resource Use: Theoretical Background Capital Theory Approach In equilibrium the returns from buying machines = the total return from holding the numeraire asset => (v t+1 + μ t+1 )/ μ t =1+ r t+1 If out of equilibrium then there is the chance of pure profits from arbitrage. The own rate of return = rental income/price If rate of return of using machines and numeraire good is different this can only be accounted for by a change in the price => v t+1 = r t+1 μ t -(μ t+1 - μ t ) So the difference in interest rates must be accounted for by a change in the price of the asset.
Capital Theory In the continuous form: where is the time derivative (increase or fall in the price of capital). This is the short-run equation of yield or the arbitrage equation.
Market Structure The market structure of an industry may be important in determining the rate of extraction of a resource. Here we will take the earlier analysis further, building on mathematical techniques of comparative dynamics.
Hotelling Rule for Monopoly
Comparative dynamics Figure 9.1 in Hanley, Shogren and White
Conclusions Initially competitive industry extracts more rapidly than monopoly but then less rapidly as the price increases towards the backstop price. Initial price for monopoly is higher than that for competitive industry. Then increases more gradually towards the backstop price, Rate of price increase for monopolist is less than discount rate, otherwise resource can be purchased by speculators, stored and sold at later date, so reducing monopoly profits.
Heroic Assumptions Non-linear extraction costs => solving for extraction path for competitive industry formidable problem Exploration issues Resource scarcity Uncertainty
Does it work? Will examine this in later lecture on empirical validation.