Hurwitz score related decision making methods Skorkovský Department of business economy Uncertainty-Risk •Although the possible returns of the investment are beyond the control of the decision maker, the decision maker might or might not be able or willing to assign probabilities to them. • •If no probabilities are assigned to the possible consequences, then the decision situation is called "decision under uncertainty". • •If probabilities are assigned then the situation is called "decision under risk". • •This is a basic distinction in decision theory, and different analyses are in order. • 2 First approach Decision (what to do ?) Alternative 1 Alternative 2 Alternative i A/O O1 O2 O3 O4 O5 A1 po11 po12 po13 po14 po15 A2 po21 po22 po23 po24 po25 A3 po31 po32 po33 po34 po35 A4 po41 po42 po43 po44 po45 Where : A=alternative(action); O=Outcome, po=payoff (benefits), (přínosy, prospěch) A=(A1,A2,…Ai) = inventory of viable options=vector, O=(O1,O2,…Ok)= outcome vector Decision Table (payoff table) 10000000 USD 500000 EUR 8000000 EUR Shares in diamond mines Bonds Antiquities Outcomes Chosen criteria I •MaxiMax –MaxiMax is the rule for the optimist. A slogan for MaxiMax might be "best of the best" - a decision maker considers the best possible outcome for each course of action, and chooses the course of action that corresponds to the best of the best possible outcomes – • 4 Choices Profit Strong market Fair market Poor market invest $8000 $800 $200 -$400 invest $4000 $400 $100 -$200 invest $2000 $200 $50 -$100 invest $1000 $100 $25 -$50 Example of the decision table I (best of the vector {800,400,200,100} is 800 !! Example II MaxiMax Payoff •Select the alternative which results in the maximum of maximum payoffs; an optimistic criterion Outcomes Alternatives O1 O2 O3 A $1,000 $1,000 $1,000 B $10,000 -$7,000 $500 C $5,000 $0 $800 D $8,000 -$2,000 $700 Maximum Payoff $1,000 $10,000 Payoff Table $5,000 $8,000 B > D > C > A Alternatives (invested amount, expectant spouse inheritance, type of the car,..) Chosen criteria II • MaxiMin –The MaxiMin decision rule is used by a pessimistic decision maker who wants to make a conservative decision. Basically, the decision rule is to consider the worst consequence of each possible course of action and chooses the one that has the least worst consequence (in our case= -50). So it is better to invest nothing !!!! • 6 Choices Profit Strong market Fair market Poor market invest $8000 $800 $200 -$400 invest $4000 $400 $100 -$200 invest $2000 $200 $50 -$100 invest $1000 $100 $25 -$50 Example II MaxiMin Payoff •Select the alternative which results in the maximum of minimum payoffs; a pessimistic criterion Outcomes Alternatives O1 O2 O3 A $1,000 $1,000 $1,000 B $10,000 -$7,000 $500 C $5,000 $0 $800 D $8,000 -$2,000 $700 Minimum Payoff $1,000 -$7,000 Payoff Table $0 -$2,000 A > C > D > B 8 A/O O1 O2 O3 O4 O5 A1 po11 po12 po13 po14 po15 A2 po21 po22 po23 po24 po25 A3 po31 po32 po33 po34 po35 A4 po41 po42 po43 po44 po45 Decision Strategy I (Hurwitz criterion allows to choose strategies depending on propensity (inclination, tendency) to risk, Example on the next slide Decision Strategy II 9 A/O O1 O2 O3 a=max b=min A1 1 5 7 7 1 A2 3 2 6 6 2 A3 5 4 3 5 3 Where ai = max (pi,Ok) and bi= min(pi,Ok) Where 5,8=7*0,8+(1-0,8)*1=5,6+0,2; 5,2=6*0,8+(1-0,8)*2,……. First line Second line Thanks for Your attention 10