Session 1.2 Discounting and Project Alternatives. Introductory Course on Economic Analysis of Investment Projects

Transcription

1 Session 1.2 Discounting and Project Alternatives Introductory Course on Economic Analysis of Investment Projects

2 Project statements Comparison of benefits and costs Typically investment costs (equipment, land, buildings etc) in early years with benefits arising after one or two years Start year when funds are committed to project (eg year 1, sometimes year 0 if starts immediately) Working capital for running project eg stocks

3 Project life Needs to be identified Can be based on technical life of main equipment or estimated economic working life Economic working life ends in year where running cost > additional revenue Where economic life < technical life need to add Terminal Value for resale of assets in final year

4 Constant prices Inflation usually ignored on assumption that all items rise at same rate Constant base year prices Not strictly correct as fixed costs or revenues will be reduced in real terms Eg tax allowances or fixed interest debt Also relative price changes eg oil price

5 Relative price change Formula RP = ((1 + p)/(1 + i))-1 where p is price rise for specific commodity and i is general inflation Approximately equal to p i So if oil price rises by 10% in 2011 and inflation is 2% relative price change for oil is approximately 8% Also applies to exchange rate

6 Identifying and Quantifying Costs - 1 Underlying principle: project cost = the cost difference with and without project, i.e., extra resources needed to produce project benefits System costs if project is part of larger system, include all other system investments needed to achieve project benefits; e.g., Power generation project may or may not need investment in transmission and distribution A highway section may or may not need investment in preceding or following sections

7 Identifying and Quantifying Costs - 2 Sunk costs those that would exist without or with the project; should not be included Contingencies determined by engineering and financial considerations Physical: monetary value of additional resources that may be required beyond base costs Price: included in financial analysis, excluded in economic analysis. i.e., economic cost is based on base cost + physical contingencies

8 Identifying and Quantifying Costs - 3 Working capital In financial analysis, includes net current assets (inventories, securities, cash, etc.) In economic analysis, include only inventories Changes in working capital are what matter Transfer payments E.g., taxes, duties, subsidies Included as cost in financial analysis, but not in economic analysis

9 Identifying and Quantifying Costs - 4 Depreciation and amortization Accounting convention allows entry as expenses, for computing tax liabilities In financial and economic analysis, such costs amount to double-counting if already counted at time of disbursement External costs Some costs may not be charged against the project, e.g., air or water pollution Such costs may be internalized, e.g., when pollution charges are imposed, or anti-pollution devices are installed

10 Base Cost Base Costs -- best estimates of project costs at a specified date, assuming: Quantities of works, goods and services and relevant prices are accurately known. Quantities and prices will not change during implementation. The project will be implemented exactly as planned.

11 Contingency Allowances Allowance for adverse conditions which will be in addition to the base cost estimate. Physical contingencies to cover physical uncertainties beyond the base case to complete the project. Often calculated and expressed as percentages of base costs. Price contingencies to cover inflation and price uncertainties. Some typical levels of Physical Contingencies: 5% - standard equipment designs/definable civil works, e.g., road surfacing, canal lining. 10% - general civil works with routine and predictable uncertainties e.g, roads, buildings, pipelines, transmission lines. 15% - plant and civil works in difficult terrain.

12 Item A. Base Cost a Zhengzhou Xi an Railway Project COST ESTIMATES AND FINANCING PLAN ($ million) Cost Estimates Financing Plan FX LC TC ADB MOR, HPG,SPG, CDB 1. Civil Works , , , Railway Track Work b Buildings and Facilities Signaling and Communications Electric Power and Traction Safety Component E-Governance and MIS Land Acquisition and Resettlement Other Equipment and Facilities Administration, Consulting Services, and Miscellaneous 11. Environmental Protection Mitigation and Monitoring 12. Temporary Facilities and Transitional Works Subtotal (A) 1, , , ,13.32 B. Contingencies 1. Physical Contingency c Price Contingency d Subtotal (B) C. Interest e Total 1, , , , ADB= Asian Development Bank, CDB = China Development Bank, HPG=Henan Provincial Government, MOR = Ministry of Railways, SPG= Shaanxi Provincial Government a At 2005 prices. Import taxes and duties are waived b Including rails, sleepers, ballast, bridge beams, track laying and bridge construction c At 8% of civil works cost, including land acquisition d At 3% per annum of local currency costs and 2% per annum for foreign exchange cost during e This is based on the prevailing US$ 5-year swap rate plus a spread for the ADB loan and the prevailing interest rate for the China Development Bank

13 Economic Cost Estimate Economist advises cost estimator on the breakdown of costs required for the economic analysis. Level of detail contingent upon availability of conversion factors and choice of numeraire. Include base cost. Include physical contingencies. Exclude price contingencies. Exclude relevant taxes, duties, subsidies, and other transfer payments. Classify project components as tradable or nontradable.

14 Discounting Future costs and impacts must be converted to present by discounting Choice of discount rate is controversial Opportunity cost rate (eg 12%) normally used where the funds would otherwise be invested productively For social sector projects a lower social time preference rate (typically 2%-3%) normally applied

15 Discounting Addresses value of time Discount factor in year t DF t = 1/(1 + i) t Reduces future values of costs and benefits Calculated simply in Excel =npv(guess,values1..n) Different interpretations of i Physical quantities can be discounted

16 Net Present Value (NPV) NPV 0 n t 0 Bt Ct R t (1 r) (1 r) B C R n n t t t t n t 0 (1 r) t 0 (1 r) (1 r) n Do not accept projects with negative NPV. For mutually exclusive projects in the same time frame without cost constraints, the project with largest NPV is favored. NPV is sensitive to discount rate.

17 Internal Rate of Return (IRR) r B C R n 0 t t NPV t n t 0 (1 r) (1 r) 0 The discount rate at which the NPV is zero called the internal rate of return (IRR). When only one project alternative is considered, the IRR can be used for project decision, i.e. only proceed with the project if the IRR is greater than the default discount rate. IRR is ratio instead of value. It should not be used to select one project from a group of candidate projects because size of the project matters.

18 GROSS BENEFITS ECONOMIC COSTS Net Non-IncremIncrem Total Capital O&M Total Economic Year Benefits Investmnt Cost Benefit Unit: USD million EIRR = 16.8%

19 Project Decisions Choosing between alternatives when benefits are not the same and can be valued Select the one with the highest, positive NPV at the chosen discount rate. IRR is not the right indicator because it does not reflect project size. Pay attention to the underlying assumptions: a) alternatives are within budget; b) alternatives have the same time frames (otherwise add terminal value to longer life alternative) Determining economic viability of the single alternative IRR> default discount rate or NPV>0

20 Cost Effectiveness Analysis Examples: Choosing from two school systems that give same educational benefits - Centralized schools that require bus transportation and more expensive smaller schools to which students can walk Two systems of electricity generation - Thermal versus hydro Two types of court systems with same disposal of cases - More court rooms at the headquarters or mobile courts Choosing amongst alternative ways of supplying potable water to communities Two or more kinds of health treatment to save lives

21 Cost Effectiveness Analysis Examples: Choosing from two school systems that give same educational benefits - Centralized schools that require bus transportation and more expensive smaller schools to which students can walk Two systems of electricity generation - Thermal versus hydro Two types of court systems with same disposal of cases - More court rooms at the headquarters or mobile courts Choosing amongst alternative ways of supplying potable water to communities Two or more kinds of health treatment to save lives

22 Case 1 Least Cost Method Drinking Water: Alternative Delivery System (A ll fig u re s in '0 0 0 ) Y e a r s Installation C ost 3000 Operating C ost Total C ost P V o f T o ta l C o s t (a t 1 2 % ) $4,932 Alternative B Y e a r s Installation C ost 4200 Operating C ost Total C ost P V o f T o ta l C o s t (a t 1 2 % ) $5,037

23 Discounting quantities Where output levels for alternatives differ it is necessary to discount physical units to make comparison Argument of cost of waiting still applies as funds committed to project would have generated returns given by discount rate

24 Cost per health impact - For Example: Benefits are measured as effectiveness (the number of Premature Deaths Prevented) Two different health programs: DPT-BCG vaccination campaign for children or AIDS treatment program both save lives. The cost per child vaccination and per patient will be computed in this case. Here the purpose is to see which programs yield more value per dollar of expenditure

25 Cost of health Project: Immunization Against DPT and BCG Ye a r Prem ature Deaths Prevented Capital Costs F a c ilitie s 2500 Equipments 8500 V ehicles 5000 Training 2000 TA 6000 Recurrent Costs Personnel S u p p lie s Training Maintenance Others Total Costs PV of Toral Benefits 12% 62, PV of Total C osts 12% $259, Cost per unit of Prem ature Deaths Prevented $4.16

26 Cost of Health Project: AIDS Program Ye a r Prem ature Deaths Prevented Capital Costs Facilities 200 Equipments 1000 V ehicles 300 Training 500 TA 1500 Recurrent Costs Personnel Supplies Training Maintenance Others Total Costs PV of Toral Benefits 12% 62, PV of Total C osts 12% $298, Cost per unit of Deaths Prevented $4.78

27 This image cannot currently be displayed. This image cannot currently be displayed. Incremental (or Marginal) Cost-Effectiveness Ratio The decision makers need to compute marginal cost-effectiveness ratios when a new larger alternative is compared with existing situation. The numerator now contains the difference between the cost of the new and old alternatives, and the denominator is also the difference between the effectiveness of the new and old alternatives: Marginal CE i C E C E This ratio in discounted present values can be interpreted as the incremental cost per unit of effectiveness. When there are several alternatives available, the marginal cost-effectiveness ratio can be used to rank the new measures versus the existing one. i i 0 0

28 Marginal Cost-Effectiveness Ratios in Prevention of Traffic Fatalities Policy Measures Total Lives Saved Incremental Effectiveness (Deaths Prevented in a Year) Total Cost (M $) Incremental Cost (Rand per Year) (M $) Marginal CE Ratios ($) Ranking A Existing ,000 B Existing plus ,000 2 Enforcement C Existing plus ,000 1 Road Safety D Existing plus ,824 3 Public Campaign

29 Limitations of cost effectiveness Does not measure Benefits in monetary terms, unless benefits are treated as costs avoided. Has to assume the activity is desirable and suggests how it can be delivered at the lowest unit cost Often analyses exclude externalities, on both cost and benefit side

30 Limitations of cost effectiveness Does not always account for difference in scale of project and scale difference may distort the choice A project with smaller size but higher efficiency level may get accepted, while another project may provide more quantity of output at a reasonable cost. Ranking by CE only strictly correct where activities are divisible so more than one small cheaper alternative can produce the same output as one larger more expensive one.

31 Scale and implicit valuation Lack of perfect divisibility can lead to unacceptable valuations For example, alternative A costs $1 mill saves 10 lives Alternative B costs $ 0.4 mill saves 5 lives A = $0.1 mill/life and B = 0.08 mill/life But accepting B means saving $0.6 mill at cost of 5 lives or $0.12 mill per life Thus caution is required as valuation may be contentious

32 Thank you.