Psychology 253/PPE 153
Judgments and Decisions, Fall 2011

MW 2-3:30, David Rittenhouse Lab A8.

mellers picture
Professor Barbara Mellers (
Office hours: Thursday 1:30-3.
Office: C1 Solomon Psychology Lab Building

baron picture

Professor Jonathan Baron (
For appointments, check my schedule and send me email.
Office: C7 Solomon

Teaching assistants:
Ann Marie Roepke (
Office hours: Wed 3:30-5:00
Office: 3701 Market Street, suite 203 (second floor, Positive Psychology Center)

Justin Landy (
Office hours: Thursday 12:30-2:30
Office: D7 Solomon


One semester of statistics or microeconomics.

Requirements that this course meets

This course counts toward the psychology major and is an option to meet a requirement for the PPE major. I do emphasize applications to public policy, as well as medical decision making.

It meets the quantitative data analysis requirement of the College. Please consider other ways of meeting that requirement.

It is an option for the consumer psychology minor, but Psych 253 does not emphasize applications to consumer psychology.

Overview and policies

This course addresses the ideal standards of judgment and decision making, and the ways in which people fall short according to these standards. Understanding of the ideals and our limitations can help improve judgments and decisions in such fields as medicine, law, and public policy.

This syllabus will be revised often. Use the reload button on your browser to make sure you have the latest version.

In particular, there will be several assignments that are not yet included.

Email, appointments, mailing list

To make an appointment with Baron, check in his web page and then send him an email message saying when you want to meet and (in at least one sentence) what it is about.

Assignments may be submitted through the web (with special forms provided for each one), or pdf if they contain figures.

The course has a mailing list, for which you can sign up, if you are not already signed up. The list has archives so that you can see what you missed or lost.

Exams, assignments, and grades There are some assignments (which are graded). You may submit drafts of the last assignment for comments, at any time during the term, up to a week before the due date. (No exceptions for any reason.) Otherwise, do not do any other assignments until told that they are ready.

The midterm and final will consist of short essay questions, and possibly short-answer questions. They will cover topics covered in class. Exams are open-book, typed, time- and page-limited, and submitted by web form. The midterm and final will be designed for two hours of work (including both writing and looking things up). The starting time is somewhat flexible. I can instruct the computer to send you the exam at a particular time. If you leave campus before the final exam, you can do it remotely. I will send exams to your Penn email address.

Grades will be based on a weighted sum of all work. Approximate weights (in percent of grade) were (last time the course was taught): assignments 35% (the last assignment being the biggest part of this), midterm 30%, final 35%. Each score will be standardized and multiplied by its weight, and then the weighted scores will be added up. Lateness will be penalized.

We will follow the rules of the University and the College of Arts and Sciences, including rules about incompletes and the Code of Academic Integrity. In particular, you may study together, but you cannot hand in identical text for any exams or assignments.

Schedule (subject to revision on short notice)

The letter T stands for Thinking and deciding. It is available at the Penn Book Center (not the Penn Bookstore). Other reading is listed with each topic. M stands for Prof. Barbara Mellers, B for Prof. Jon Baron, L for Justin Landy, and R for Ann Marie Roepke.

Links for the names of topic go to slides that we will present in class. You should be able to print these if you want to, before class. But please wait until the last minute to do that. To print Baron's slides using Firefox without wasting paper, use the menus: "View / Use Style / print," then "File / Print." The slides are not intended as a complete outline.

9/7 Introduction (M): T1-3.

9/12 Multiattribute decisions (M): T13, T14

9/14 Decision analysis (M): T5

9/19 Probability (B): T5, Strogatz on Bayes's theorem,
Class activity and homework on personal probability estimation. Wikipedia page (very good reference, not required)

Assignment 1 due at the end of 9/20 (Tuesday)

9/21 Hypothesis testing (B): T7, Intelligent design

9/26 The value of information (M)

9/26 Assignment 2, first part due by the end of the day

9/28 Logic (B): T4.

10/3 Heuristics in probability judgment (M): T6.

10/5 Midterm

10/7 Assignment 2, second part due at the end of the day.

10/12 Irrational belief persistence (L): T9.

10/17 Subjective well-being (R)

10/19 Money and happiness (M)

10/21 Assignment 3, first part due at the end of the day.

10/24 Utility (B): T10-11.

10/26 Reference dependence in choice (B): T12,

10/28 Assignment 3, second part due at the end of the day.

10/31 Risk (B): T20, Airport security follies, The odds of airborne terror (Nate Silver)

11/2 Intertemporal choice (M and B): T19

11/7 Correlation and contingency (B): T8.
(and will begin Moral thinking, T16)

11/9 Moral thinking and utilitarianism (B): T16.

11/14 Fairness (B): T16, T17, Bailout (Collins)

11/16 Exercise on negotiation (M)

11/21 Negotiation (M)
Supplement (with Bazerman example)

11/23 Social dilemmas (B): T18,
G. Hardin (1968), The tragedy of the commons. (Science, 162, 1243-1248).
Approval voting (Wikipedia)
Edlin et al.: Vote for charity's sake

11/28 Voting (B)

11/30 Linear models of judgment (M): T15.

12/5 Carter racing exercise (M)

12/7 Review (M)

12/16, 6-8 PM Final exam default time

Assignment 1: Multi-Attribute Utility Analysis

Carry out a multi-attribute analysis for your partner, and he or she will do the same for you. Take a decision that matters to him or her (a nontrivial personal decision). Here is a link to the form in which we want you to submit your homework.

Describe your partner's decision problem.

Make sure that your partner comes up with at least three options and at least three attributes and at least 2 levels of each attribute. Repeated decisions such as what to have for lunch are more difficult than they seem, because the real options are policies.

Ask you partner what he or she views as the most important or "fundamental" values. For example, your partner might face a career decision. Many of the things that people say when asked for their values are superficial, e.g., that they want their career to be "interesting." What is interesting to you may depend on bigger issues about what you want to do with your life and/or what you think you should do with your life. Not easy questions.

This is not a paper. You don't need to go on at great length describing the decision in words. Just include the minimum to make it clear what the decision is about, and what the attributes are, if that is not clear from their names. List the attributes, with the top and bottom of the range of each.

Judge the relative importance of attributes by distributing 100 points among those attributes. Explain in detail how you made the judgments that yielded the attributes weights. Give an example.

Construct a table of your analysis, with the options, attributes, attribute utilities and weights. The weights should be the last row, at the bottom. Show completely the calculation of the utility of the best option. If the outcome is a close call, make some changes in the utilities and weights to see how easy it would have been for another option to be in first place.

Discuss the results. Was the option that maximized your partner's utility consistent with his or her intuition? What did your partner learn?

Last assignment (due last day of classes, Dec. 9, by end of the day): Discussion paper.

Write a short (absolute maximum 200 lines, 70 characters per line; minimum 25 lines) reflective discussion of some topic from the course. (Here is a form.) This should require no additional research, although you should of course acknowledge any sources that you use because you already know them (including course reading). Do not feel obliged to fill up the 200 lines; 125 should suffice if you write succinctly.

One possible format for this paper is a philosophical discussion of some question from the course, such as whether self-deception is rational (but probably not that one). Try to avoid questions that have completely trivial answers and questions so big that a book would be required to answer them. Avoid mere recapitulation of arguments in the reading as well as unsympathetic attacks on it. Avoid one-sided presentations that ignore the arguments of the other side. Feel free to ask if a topic is appropriate. A good model to follow is the discussion of self-deception on pp. 71-73 of the text, especially the discussion of whether self-deception can be rational. Feel free to skip ahead in the reading if you wish to hand in the paper early. If you choose this kind of topic, make sure to consider (and rebut, or take into account) objections to arguments you make.

Another possible format is something more like a research proposal. Take a result from the course, propose alternative explanations of it, and suggest ways of distinguishing them.

Grading of this assignment: If a paper does a good job summarizing the course, it is a B (8/12). It must say something beyond the course to get an A (11/12). But it must also consider obvious counter-arguments; failure to do that could drag it down, even below B. If I'm blown away by the writing, I give a higher grade, even A+ (12). If the writing is so incoherent that I cannot understand the ideas, I lower the grade. If 2 or more big problems are present (nothing original, one sided, badly written), the paper can get a C (5) or D (2). F (0) is reserved for papers that have nothing to do with the course, or are not submitted.

Last modified 12/12/11

Valid HTML 4.01!