AGEC 352Final Project

March 19, 2012R. Keeney

Overview

• Term paper describing model and analysis of food diets

• Requirements– Part 1: Minimum cost subsistence diet

• All constraints describe minimum requirements of nutrients• Written analysis and discussion

– Part 2: Student posed question • Problem description • How constraints, objective address question• Written analysis and discussion

Guidelines for project paper

No more than 6 double spaced pages of text Most A papers are 3-4 pages

Tables/Graphs at the end don’t count Must use at least 20 foods in your models

Graded as your final exam (class has no final)

Submit a printed copy Due on Wednesday of Finals Week (4PM)

Project resourcesWill be posted on class website

Sample paper from former student▪ Considers subsistence in part 1▪ Addiotional cost of balanced diet (food pyramid) in part 2

Final Project Description (details on the assignment) List of Readings (not required)▪ Academic work in economics and nutrition on the cost of foods and

health issues Diet recommendation tables▪ Use this to look up the daily requirements (constraint RHS)

Example spreadsheet model: McD’s Subsistence Database (after Assignment 1 completed)

Database

• Constructed by the class• Assignment 1 (15% percent of project grade)– Due March 28– Submit in groups of 3 – Collect and submit information on 30 different foods

• Price per serving• Nutritional content per serving

– Format correctly and submit via email to• aremble@purdue.edu

Format

• Attach spreadsheet to an email• In the body of the email list the group members

(no more than 3, no less than 2)– If your data is submitted but not usable: half credit

for assignment• Check it closely: this is the point of doing it in groups• Most common mistake is not having information on per

serving basis– Easiest way to format: overwrite your information in

the example spreadsheet

Long Name Abbreviation Price Blank Calories Fat Sodium Carbs Fiber Protein Vitamin A Vitamin C Calcium IronDollars Cal Grams Milligrams Grams Grams Grams %2K %2K %2K %2K

McD Hamburger mdhb_rmk 0.8 250 9 520 31 2 12 0 2 10 15McD Cheeseburger mdcb_rmk 0.95 300 12 750 33 2 15 6 2 20 15McD Dbl Cheese mddc_rmk 1 440 23 1150 34 2 25 10 2 25 20McD Quarter Lber mdqp_rmk 1.95 410 19 730 37 3 24 2 4 15 20McD Quarter Lber w/cheese mdqpc_rmk 2.1 510 26 1190 40 3 29 10 4 30 25McD Dbl 1/4 Pounder mddqp_rmk 2.95 740 42 1380 40 3 48 10 4 30 35McD Big Mac mdbmac_rmk 1.99 540 29 1040 45 3 25 6 2 25 25McD Big n' Tasty mdbnt_rmk 2.5 460 24 720 37 3 24 6 8 15 25McD Big n' Tasty w/ Cheese mdbtc_rmk 3 510 28 960 38 3 27 10 6 20 25McD Filet o' Fish mdfof_rmk 1.99 380 18 660 38 2 15 2 0 15 10McD McChicken mdchick_rmk 2.75 380 16 790 40 1 14 0 2 10 15

McDonald’s Subsistence: Example

• An Example:– Using 11 McDonald’s sandwiches to construct a

least-cost subsistence diet• Subsistence: a diet that meets a set of minimum

requirements only– Look at some alternative questions based on the

solution to the subsistence problem

The Data

• Vitamin C and Calcium are expensive in these foods

• 5$ to get a day’s Ca from Dbl Cheese

0

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Cost

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McD's Sandwiches

Vit C Calcium

The Data

• Fat and calories are relatively cheap to get from these foods 0

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Fat G

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McD's Sandwiches

Cal/$ Fat/$

The Model

• Least Cost-Subsistence Model– Must get minimums (30 yr old male) according to

daily dietary recommendations• Calories = 2500• Fat = 0• Sodium = 2300 mg• Carbohydrates = 130 gm• Fiber = 38 gm• Protein = 56 gm• Vitamins A & C, Ca, Fe = 125% (of 2000 calorie diet)

The SolutionTotal Costs = $40.44

Foods▪ 3.68 Double Cheeseburgers▪ 14.71 Big n’ Tasties

Binding Constraints▪ Vitamin A and Vitamin C

Other thoughts▪ High fat, calories, and carbs (438 gm fat, >8000 cals, 670 gm carbs)▪ Shadow prices tell me that if I want to consider alternative

nutrient sources, every pct point in Vit A can lower costs by $0.04, and pct point in Ca can lower costs by $0.28.

McD’s plus a Vit C supplement

• Add a vitamin C supplement to my model using its cost per serving and nutritional information

• $.11 per tablet, 1667% of daily VitC and 11% of daily Ca

• New solution– Total Costs = $17.71, same binding

constraints plus fiber– Still high calories, fat, and carbs

Upper bound on grams of fat

• At 100 and 200 grams of fat as an upper limit, there is no solution– You can not meet the minimum nutrition without

exceeding 200 g of fat using these sandwiches• At 300 grams of fat get a solution– That’s still pretty high– Probably want to look at the McD’s menu salads

and other items to try and find some lower fat foods if pursue the upper limit on fat intake

Ideas for your Project: Activities

Comparison models Type A diet vs Type B diet Food away from home vs prepared at home▪ Is the cost difference enough to justify the time spent

preparing foods?Supplementing of diets with limited foods

With only 20 foods, a couple of constraints are going to determine your costs▪ Adding a food (or supplement) rich in the binding

constraint from the subsistence solution will lower costs

Ideas for your Project:ConstraintsSubsistence in a 20 food model gives weird solutions (eating

high quant of few foods)Adjusting the constraints to reflect health considerations

and what those health considerations might cost works well Diabetic or other restricted diet costs▪ Upper bound limitations on some nutrients

Sample paper from finds that balanced diet (food pyramid), doubles costs

Exercise based or other commercial diets

See the annotated bibliography for other ideas

Final Tips

• Use what you have learned in class– Look to shadow prices of your initial subsistence

model to see which constraints and foods are driving the final cost

– Look to excess constraints (slack) to see where you might address health concerns such as high fat etc.

– Look to objective penalties to find out what foods are the worst for a cost minimizing consumer