Tuesday, October 25, 2011

Managerial Economics - ECN7302

Managerial Economics (ECN7302) - Megan Way, mway@babson.edu, x5892


Session 1: Oct 25th, 2011


Economics: Study allocation of scarce resources.
Economic systems are set up to allocate scarce resources

  • Centralized common control (USSR, North Korea)
  • Mixed market
    • We let the market function
    • give regulation, provisioning of some goods etc.
  • Free market  
questions:
  1. What is produced?
  2. How is it produced?
  3. Who is it produced for?

Individuals are trying to maximize - utility
Firms are trying to maximize - profits
Govts are trying to maximize - welfare

Consumers:
Rational choice, we assume rational.
Traditional economics assume that people are rational., (There is new concept of behavioral economics in which people somewhat do not behave rationally)

Utility:
satisfaction, happiness, value to consumer
Marginal utility:- utility from teh next unit of teh good
Diminishing MU:- more consumed in a time period lowers the utility of teh next unit.
How do we measure utility: by either bringing in units like "Util" OR we rank it against something else

Maximizing utility subject to:

  • preferences - 
    • assume that they are complete (you will never say i dont know)
    • assume that the preferences are transitive
    • assume that "more is better"
    • assume (preferences are stable over time)
  • income
  • prices of all goods
Then we move to the discussion of indifference curves for the utility. See page 5 of lecture notes.
Bring in the budget constraint now.
The budget constraint is a straight line with decreasing slope when drawn with Price of Q1 on y and price of Q2 on y.
Draw an indifference curve on top of the budget constraint line. Move to the point where indifference curve is tangent to the budget constraint line. 

At equilibrium (when you have maximized utility) your MRS (marginal rate of substitution) will be = -Px/Py [only at equilibrium]
otherwise marginal rate of substitution MRS = delta Qy/ delta Qx 

What can you as a marketing person to influence the equilibrium point.
either change the price to change the slope of the budget contraint line. OR do advertisement to change the utility curve.


Session 2: Oct 27, 2011


Discussion on the assignment.


Session 3; Nov 1, 2011
Assignment



1.      Mr. Smith has the following demand equation for a certain product:
Q = 30 - 2P.
a)      At a price of $7, what is the point elasticity?
Ans: P=7 => Q = 30 - 14 = 16
point elasticity = dQ/dP * P/Q
dQ/dP = -2
P/Q (at P=7) = 7/16
PED = -7/8 = -0.87

Interpretation: if i raise the price by 1% the quantity demanded will go down by 0.87%


b)      Between prices of $5 and $6, what is the arc elasticity?
Ans: at P=5; Q=20 and at P=6; Q=18
E = delta Q / delta P * (P1 +P2) / (Q1+Q2) ; (20-18)/(-1)*(6+5)/(18+20) = -11/19 = -0.579
Interpretation: if i raise the price by 1% the quantity demanded will go down by 0.579%


c) If the market is made up of 100 individuals with demand curves identical to Mr. Smith’s, what are the point and arc elasticities for the conditions specified in parts a and b?
no change
Interpretation: because the elasticities are calculated in terms of %ages, we have eliminated the number of products sold from our equation that way.




2.      Deck & Blacker (DB) makes small kitchen appliances.  DB hired a consulting economist to estimate the demand for toaster ovens.  The consultant used data gathered from DB’s sample market survey.




Qx =    40   -   1.1Px   +   0.1Pc   +   0.32I   +   1.5Ax

                    (2.06)     (.06)       (.003)        (4.31)          (.5)






Qx is the quantity demanded in thousands;  Px is the price in dollars;  Pc is the price of leading competitor; I is the mean household income, measured in thousands;  Ax is the company advertising expenditure (measured in thousands of dollars).  (Note: The figures in parenthesis are standard errors of the coefficients.  The regression analysis also provided the coefficient of determination, which is 0.75.  This information can be omitted in answering the questions below.)



The current values of the independent variables are:  Px = 55; Pc = 50; Ax = 20; and I = 31.  Please answer the following questions:






a) Current level of sales, Qx , is: 40 - 1.1(55) + 0.1(50) + 0.32(31) + 1.5(20) = 24.42
b) point elasticity = -1.1* 55/24.42 = -2.4 (if i lower my price by 1% quantity demanded will go up by 2.4% so yes we should consider lowering the price for higher revenues.
c) What is the total revenue maximizing price for Deck & Blacker toaster ovens?  Graph the demand and marginal revenue curves.  Plot the revenue maximizing price and output.
Ans: Qx = f(Px,Pc,I,A)
        Qx= f(Px) (keeping all teh rest of the variables constant)
        Qx= 40 - 1.1(Px) + 0.1(50) +32(31) =1.5(20)
        Qx = 84.92 - 1.1Px
        Qmax = 84.92
=> P = 77.2 - 0.91Qx

Total Revenue, TR = P * Q
TR = (77.2 - 0.91Qx)*Qx
TR = 77.2Qx - 0.91Qx^2
dTR/dQx = 77.2 - 2(0.91)Qx
dTR/dQx = 77.2 - 1.82Qx
Marginal Revenue = dTR/dQx
Total revenue is maximum at the tangent when MR = 0
So, put dTR/dQx = MR = 0 and solve for Qx
77.2 - 1.82Qx = 0
-> Qx (max) = 48.46




d) How concerned should DB be about price discounts by its leading competitor?  Explain.
Ans: Price demand by competitor
cross Price elasticity % delta Qb / % delta Pc
elasticity(x,c) = dQ/dPc * Pc/Q
                    = (0.1)*(50/24.42) = 0.2

elasticity (xc) < 0 complements
elasticity (xc) > substitutes 
this implies that teh two products are substitutes
So, if the competitor gives the discount WE SHOULD be concerned

e) How concerned should DB be about the prediction that the country is slipping into a recession?
Ans: We should be looking at teh income elasticity
elasticity(I) = % delta Q / % delta I = dQ/dI * I/Q = 0.32 * (31/24.42) = 0.406

elasticity(I) > 0 - normal good
elasticity(I) < 0 inferior good
elasticity(I) > 1 luxury good ~ superior good
this implies that since this is a normal good, recession will have a negative effect on our sales->revenues
as

f) How effective do you think advertising is for this company?
Ans: elasticity(A) = %delta Q / % delta A = dQ/dA * A/Q = 1.5 * (20/24.42) = 1.23

say A1 = 20,000 and A2 = 20,200 (1% increase)
-> Q1 = 24,420 and Q2=(1.0123)*Q1 = 24,720
so this means that an increase of $200 of advertising gives us 300 units of additional sales
lets see the effect on revenue
TR = P*Q
delta TR = 55*300 = 16,500
so this implies an extra spending of $300 will give us an additional revenue of $16,500

---------------------------------------------------------------------

Cost calculations:
Lets say we have Marginal Cost, MC or $20
if we have MC=$20
so to maximize profit, we put MR = MC
77.2 - 1.82Qx = 20
=> Qx = 31.43 this teh quantity which will give us teh maximum profit.
we can get teh price for this quantity
P = 77.2 - 0.91*(31.43)
   =  $ 48.6
Rule: Profit maximization - MC = MR

Consumer surplus:



There are externalities as well. There are spill overs.
See lecture notes on externalities.

Session 4: Nov 3, 2011


Production and cost theory
Production function, Q = f|(K,L)
K refers to fixed capital, its not just the $

short run vs the long run
short run = time period in which at least one input is fixed
long run = all inputs vary

Q = Total product (TP)
APL = TP/L = Q/L
MPL = delta TP/ delta L = delta Q / delta L

Diminishing Marginal Returns: As you add variable input to a fixed input you hit point where variable input is less productive

W/APL = Avg cost
e.g. W/APL Germany < W/APL Greece (even though the wages are higher  in Germany)

Cost Terminology
Accounting costs: explicit
Economic costs: explicit + implicit
explicit: monetary outlays
implicit: foregone earnings (opportunity costs)
implicit: what you could earn with the next best use of your resources

sunk cost:

anything that increases productivity decreases cost
SO the cost functions and the productions are a mirror image of each other.
Total Cost Tc = FC + VC
ATC = TC/Q  ;  AFC  FC/Q  ; AVC = VC/Q  ; MC = delta TC / delta Q

Profits = (P-ATC)*Q
Breakeven point = where MC intersects the ATC
Shutdown rule P<AVCmin

shutdown point is the minimum AVC


Session 5: Nov 8, 2011



1.      Little Dolls Corp. is considering the installation of plant and equipment to manufacture talking dolls.  It has a choice of three plant sizes A, B, and C.  The average cost schedules for these plants are shown below.  Also shown is the estimated probability of demand for each of the first two years.

Output Level
Demand Probability
Expected Demand
Average Cost Level $
Plant A      Expected ACA       Plant B        Expected ACB    Plant C       Expected ACc
1000
0.10
100 
110
11000 
140
14000 
180
18000 
2000
0.20
400 
90
 36000
100
40000 
110
 44000
3000
0.35
 1050
80
 84000
70
73500 
80
 84000
4000
0.20
 800
80
 64000
60
48000 
50
40000 
5000
0.10
 500
90
 45000
70
 35000
40
20000 
6000
0.05
 300
110
 33000
90
 27000
50
15000 



















a)      Comment on the existence of economies and diseconomies of plant size, if any, in this company.  Graph the cost curves.
b)      Calculate the expected value of average cost for each plant and expected value of quantity demanded given the probability distribution.  Note: Expected value is:
Σ Xi Pi , where Xi is an individual outcome and Pi is the probability of that outcome.
c)      Which plant size would you recommend to the management of Little Dolls Corp.?  Support your answer by explicitly addressing the assumptions and decision criteria used in your recommendation. Would you change your recommendation regarding the optimal plant size if you knew that a relatively conservative management runs this company?
d)      Given the plant size you have recommended, how much excess capacity will Little Dolls Corp. have?



-----------------------------------------------------------
Class notes:
Full capacity = when MC begins to rise above ATC. This will be when the ATC is minimum, this will the most efficient point. 

ATC = SRAC (short run average cost)

LRAC (Long run average cost): least cost of production at any output level when all inputs are variable. That is its called Planning curve. 


Session 6: Nov 10,2011


Salem Telephone company
Variable costs:
Power - $4.7/hr
hourly staff - $ 24.00
AVC = 28.7

(P-AVC) contribution
800-28.7 = 771.30 (hourly cont commercial)
400-28.7 = 371.30 (hourly cont intra-company)
Total fixed cost = 212,000 (add all except the variable costs)
Total fixed cost not covered by intra-company sales
= 212000 - 205(400 - 28.7)
= 136,900

break-even quantity, Q = 136,900/(800-28.7) = 177 hours

------------------------------------
Lets calculate elasticities for Salem
Arc elasticity
P1 = 800, P2 = 1000
Q1 = 138, Q2 = 97
Arc elasticity = -1.57021 (in the elastic range)

P2 = 600
Q2 = 179
Arc elasticity = -0.9 (in the inelastic range)

For
TR =


Session 7: Nov 15, 2011


Degree of Operating leverage
DOL = % change in profit / % change in Q

assuming no pricing power and constant AVC
=> profit = (P-AVC) * delta Q / (P-AVC-AFC) * Q
                = (P-AVC)

if operating leverage is higher .. you have higher profit potential after the breakeven point but at the same time below the breakeven point the loss potential is also higher.

Externalities


Negative externality - cost is borne by society.

Session 12: Dec 1, 2011

Value Pricing in Domestic and International Markets


1.      Palm has identified Europe and Asia as two new areas of potential market entry for its new Palm tungsten T PDA model.  Estimated demand equations for these two markets, respectively, are:

QE = 400,000 – 444.44 PE                   and      QA = 790,622 – 1,090.51 PA

For simplicity assume that transportation and other international transactions costs are negligible, and that free trade exists among all the countries in these areas and the US.  On the manufacturing side, the same cost conditions apply to these markets as well, with a constant AVC of $220 per unit.

Palm has decided to pursue a price discrimination policy that supports short-run profit maximization (skimming) for each of the two new markets.  Use this information to calculate the profit-maximizing quantities and prices for Europe and Asia.  (In calculating coefficients, please use five decimal places).


VC = AVC*Q
VC = 220Q
MC = dVC/dQ = 220


For Europe
Pe = 900 - 0.00225Q
MR = 900 - 0.0045Q


at profit maximization MR = MC
900 - 0.0045Q = 220
Qe = 151,109
Pe = 560


Contribution:
per unit:560 - 220 = 340
total = 51,377,060


Asia


Pa = 725 - 0.0009Q
MR = 725 - 0.0018Q


at MR = MC
725 - 0.0018Q = 220
Qa = 275,354
Pa = 474
Contribution/unit: 474 - 220 = 254
total: 69,939,916
Total Asia and Europe = 120,643,627
--------------
part b)
combined demand equation:
Q = 1190622 - 1535P
P = 776 - 0.0006Q
MR = 776 - 0.0013Q
MR = MC
776 - 0.0013Q = 220
Q = 427,438
P = 497.84


Contribution: 497.84 - 220 = 277.84
total cont = 118,759,373.92
-----------------------



2.      TLC Lawn Care, Inc. provides fertilizer and weed control lawn services to residential customers.  Its seasonal service package, regularly priced at $250, includes several chemical spray treatments.  As part of an effort to expand its customer base, TLC offered $50 off its regular price to customers in the Wellesley area.  The response was enthusiastic, with sales rising to 5,750 units from the 3,250 units sold in the same period last year.
a.       Calculate the arc price elasticity of demand for TLC service.

Assume that the arc price elasticity (from part a.) is the best available estimate of the point price elasticity of demand.  If marginal cost is $135 per unit for labor and material, calculate TLC’s optimal markup on price and its optimal price.  Comment on TLC’s current prices.


P1 = 250
P2 = 200
Q1 = 3,250
Q2 = 5,750


elasticity = [delta Q / delta P ]*[(P1+P2)/(Q1+Q2)]
elasticity = -2.5


Assume that the arc price elasticity (from part a.) is the best available estimate of the point price elasticity of demand.  If marginal cost is $135 per unit for labor and material, calculate TLC’s optimal markup on price and its optimal price.  Comment on TLC’s current prices.
M (Optimal markup) =[ -1/(1 - |elasticity|)]*MC 
1 + M = E/(1+E)
TLC arc E = -2.5
1+M = -2.5/(1-2.5) = 1.667
M = 0.667
M = 66.7%


MC = 135
M = 66.7%


Session 14: Dec 6, 2011


Case; P&G - Wal-mart partnership


Diaper market:
Characteristics - elasticity
Luxury vs necessity - inelastic
number of substitutes - cloth - inelastic
% of budget - relatively high - elastic
Time frame


Market structure
- Differentiated
- # of firms - few (3-4)
- Barriers to Entry - high, R&D, high FC, economies of scale, distribution, brand
- Pricing power - decide their own price
- Interdependence 
Oligopoly


Apply game theory on the case
Kimberly Clarke and P&G have options of either go premium or promotional pricing
P&G, KC




























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