Lecture 14: Diet Problem/Intro to Final Project

1. Lecture 14: Diet Problem/Intro to Final Project AGEC 352 Spring 2011 – March 21 R. Keeney

2. Final Project • Tomorrow • Start back in on transportation problems • Lab with discussion questions etc. • Today • Discuss final projects for AGEC 352

3. Diet Problems • Of longstanding interest: • Impoverished nations and the poverty problem • What does it cost to provide enough food? • Food inflation and costs • How has the minimum cost diet changed over time? • Food costs, low income, and health • Are problems like obesity more prevalent in low income households due to types of foods that are most affordable?

4. Linear Programming • Most common tool used in analysis of diet costs • Blending problem • What combination of foods satisfies a set of daily requirements at lowest cost? • (See fertilizer mix or cereal problems) • Key issue: • What values and nutritional factors to use in the constraints?

5. Subsistence Problem • In the 1940s, Stigler was worried about world hunger and conducted a study of the cost of subsistence • Subsistence = staying alive • Collected information from health research and food products to estimate the cheapest way to eat enough to survive

6. Stigler • You are required to read the paper • Link provided on class website • Read closely enough to answer the following questions: • What does he state as his purpose for study? • What are his primary findings? • What comparisons does he make between foods and years on diet cost? • What method did he use?

7. Final Project • Assignment #1 • Part of the project grade requires you to collect data and submit • Details in Part I of the handout provided • Submit a spreadsheet with information on cost and nutrition data for 15 different foods • Each student required to submit data • If you work together, find 30 foods and split them up. Do not submit the same lists. • No beverages, no more than 5 restaurant foods

8. FP Assignment #1 • Cost on a per serving basis • E.g. Can of Pringles cost $1.50 • Six servings -> $0.25 per serving • Nutrition facts on the package should be reported per serving • Report on 15 items and submit the spreadsheet to aremble@purdue.edu • Deadline is Friday at noon

9. FP Assignment #1 • Information required • Specific format must be followed • Price on a serving basis • No formulas in the spreadsheet you submit • Make sure you report the units and not the percentages for the first six items • Both will be shown • Report the percentage for the last four items as a whole number

10. Example Nutrition Facts Report as the quantity/weight amount. Report as percentages: Use the whole number not the proportion or %.

11. Spreadsheet format • Use the example McDonald’s spreadsheet as a template. Just delete the McD foods and type in your information • Remember: no formulas • Save the spreadsheet as fooddata_yourinitials.xlsx or .xls • Email to aremble@purdue.edu • Put Food Data 352 in the email subject line

12. Final Project • Amber will compile the data submitted by students and post to the course website for everyone’s use • Use this database to build an LP diet model for your final project • Two Parts • 1) Subsistence model: Lowest cost diet that meets minimum requirements • 2) Your choice: propose a question and change the model to deal with that question

13. Part I: Subsistence Model Example RHS values for a subsistence model. Assumptions: 30 years old Male Mildly active See the DRI tables for other assumptions. Note the last 4 items are just scaled to the size of the diet. 125=(2500/2000)*100

14. Part II • Requirements • LP model used to address your question • Simple questions • Vegetarian vs. mixed food model • Upper bounds as well as lower bounds on nutritional items • e.g. 2500 < = Calories < = 2750 • Other questions • Cost of food pyramid guidelines (integer constraints) • Cost of being diabetic or bulking up (constraint information)

15. Other requirements/information • You must use at least 20 foods and no more than 40 foods • The paper must not exceed 6 pages of text • 10 point font min. • 1 inch margin min. (all sides) • No title page (just use the upper left corner) • All tables at end of document (solution and sensitivity)

16. Other information • Submit a hard copy to me • Thursday of Dead week = Bonus (5%) • Wednesday of Finals week • Late penalty = -25% of project grade • 20 percent of your final grade and replaces final exam

17. Grading criteria • Part I • Common question -> comparative grading • Best answers will receive the highest scores. • Effectiveness at interpreting results and sensitivity and communicating those in words will be the primary basis of the score. • Part II • Different questions -> grade based on execution • How well does your approach match the question you pose and do you make the reasoning clear? • Also the solution interpretation and communciation of findings (answer to your question).

18. Lab Tomorrow • Continue working with the Eurotrans model • If you haven’t completed the handout from last week, try and get caught up before lab starts tomorrow because we will continue from the last part of that assignment • Answers to HW 5 questions are due on Wednesday. • Quiz on Wednesday over the Transportation Model handout.