Optimal Decisions Using Marginal Analysis

Chapter two

Managerial Economics, 8e

William F. Samuelson ● Stephen G. Marks

RECAP

Chapter 2: Optimal Decisions Using Marginal Analysis

U = number of actual users

M = number of potential users

a = % of actual users lost in each period

b = % of potential users gained in each period

The sustainable user base is:

RECAP

Chapter 2: Optimal Decisions Using Marginal Analysis

= cost of reducing a by 1%

= cost of increasing b by 1%

The optimal allocation of the marketing budget is:

Calculate the derivatives and find the optimal ratio

RECAP

Chapter 2: Optimal Decisions Using Marginal Analysis

The derivatives are:

EXAMPLE 1: MICROCHIP MANUFACTURER

Demand:

Revenue:

Chapter 2: Optimal Decisions Using Marginal Analysis

Other factors than price that may impact demand are held fixed. They would affect the parameters.

Sales are lots (of 100 chips) per week.

Price per lot is in thousands of dollars.

Figure 2.1 The demand curve for microchips

Chapter 2: Optimal Decisions Using Marginal Analysis

Figure 2.2 revenue from microchips

Chapter 2: Optimal Decisions Using Marginal Analysis

EXAMPLE 1:

Cost:

Profit:

Chapter 2: Optimal Decisions Using Marginal Analysis

Quadratic function that increases, then decreases.

Cost is in thousands of dollars.

Fixed cost: $100K per week. Variable cost: $38K per lot.

Figure 2.3 The cost of microchips

Chapter 2: Optimal Decisions Using Marginal Analysis

Figure 2.4 Profit from microchips

Chapter 2: Optimal Decisions Using Marginal Analysis

Figure 2.5 A close-up view of profit

Chapter 2: Optimal Decisions Using Marginal Analysis

EXAMPLE 1:

Profit:

Chapter 2: Optimal Decisions Using Marginal Analysis

Derivative of Q) is the slope of the profit function at Q. Slope is zero at that maximizes profit.

Recall the profit function.

First-order condition:

→

Figure 2.6 Total profit and marginal profit

Chapter 2: Optimal Decisions Using Marginal Analysis

DIFFERENTIATION

Chapter 2: Optimal Decisions Using Marginal Analysis

Suppose we have a function of the form:

The derivative is:

Special cases:

DIFFERENTIATION

Chapter 2: Optimal Decisions Using Marginal Analysis

For instance, for the function:

Derivatives of the additive terms are:

DIFFERENTIATION

Chapter 2: Optimal Decisions Using Marginal Analysis

The derivative of a sum of terms is the sum of the derivatives of the additive terms:

So:

EXAMPLE 2:

Profit:

Chapter 2: Optimal Decisions Using Marginal Analysis

Derivative of Q) is the slope of the profit function at Q. Slope is zero at that maximizes profit.

Suppose we have a quadratic profit function.

First-order condition:

→

Figure 2A.1 The Firm’s Profit Function

Chapter 2: Optimal Decisions Using Marginal Analysis

EXAMPLE 3:

Chapter 2: Optimal Decisions Using Marginal Analysis

Consider hypothetically a cubic profit function:

It has two flat points, where its derivative is zero. One is a minimum, one is a maximum.

Profit:

Figure 2A.2 A Second Profit Function

Chapter 2: Optimal Decisions Using Marginal Analysis

EXAMPLE 3:

Chapter 2: Optimal Decisions Using Marginal Analysis

Recall the cubic profit function:

Solutions of the first-order condition are Q = 2 and Q = 10. For a maximum, we also need > 6:

First-order condition:

Second-order condition:

MAXIMA AND MINIMA

Chapter 2: Optimal Decisions Using Marginal Analysis

Near a maximum, a function rises, then falls. Its derivative changes from positive to negative and keeps declining. The derivative of its derivative is negative.

Near a minimum, a function falls, then rises. Its derivative changes from negative to positive and keeps increasing. The derivative of its derivative is positive.

EXAMPLE 4: MULTIVARIATE OPTIMIZATION

Profit:

Chapter 2: Optimal Decisions Using Marginal Analysis

Maximize separately with respect to P and A.

Suppose the firm simultaneously decides on pricing and an advertising budget.

First-order conditions:

EXAMPLE 4:

Chapter 2: Optimal Decisions Using Marginal Analysis

Solve jointly by substituting one into the other.

Recall the dual first-order conditions.

EXAMPLE 5: CONSTRAINED OPTIMIZATION

Profit:

Get Professional Assignment Help Cheaply

Are you busy and do not have time to handle your assignment? Are you scared that your paper will not make the grade? Do you have responsibilities that may hinder you from turning in your assignment on time? Are you tired and can barely handle your assignment? Are your grades inconsistent?

Whichever your reason may is, it is valid! You can get professional academic help from our service at affordable rates. We have a team of professional academic writers who can handle all your assignments.

Our essay writers are graduates with diplomas, bachelor's, masters, Ph.D., and doctorate degrees in various subjects. The minimum requirement to be an essay writer with our essay writing service is to have a college diploma. When assigning your order, we match the paper subject with the area of specialization of the writer.

Why Choose Our Academic Writing Service?

Plagiarism free papers
Timely delivery
Any deadline
Skilled, Experienced Native English Writers
Subject-relevant academic writer
Adherence to paper instructions
Ability to tackle bulk assignments
Reasonable prices
24/7 Customer Support
Get superb grades consistently

How It Works

1. Place an order

You fill all the paper instructions in the order form. Make sure you include all the helpful materials so that our academic writers can deliver the perfect paper. It will also help to eliminate unnecessary revisions.

2. Pay for the order

Proceed to pay for the paper so that it can be assigned to one of our expert academic writers. The paper subject is matched with the writer’s area of specialization.

3. Track the progress

You communicate with the writer and know about the progress of the paper. The client can ask the writer for drafts of the paper. The client can upload extra material and include additional instructions from the lecturer. Receive a paper.

4. Download the paper

The paper is sent to your email and uploaded to your personal account. You also get a plagiarism report attached to your paper.

smile and order essay PLACE THIS ORDER OR A SIMILAR ORDER WITH USA ELITE WRITERS TODAY AND GET AN AMAZING DISCOUNT

Get Professional Assignment Help Cheaply

Why Choose Our Academic Writing Service?

How It Works

1. Place an order

2. Pay for the order

3. Track the progress

4. Download the paper

Leave a comment Cancel reply