# Microeconomics 1

## Main course materials

The main reference for my half of the course is
my lecture notes.
Please regularly check that you have the latest version.
I last updated the notes at
10:33PM, Tuesday 18 of June.
You can see what changed using Adobe Acrobat Pro on the uCreate computers.
Choose `Tools -> Compare Documents`

, and select the PDFs containing
the old and new versions of the notes.
You can download the Latex source if you
want to annotate or contribute improvements to the notes.

You can read the Assessment guide with practice exam questions and sample solutions with commentary.

You can browse last year's course materials.

## News

- January 22: sample solutions are now available for the December exam.
- Week 5
- Watch Existence of equilibrium (5.6). You can read the whiteboard.
- Watch Second welfare theorem (5.7). You can read the whiteboard.
- Watch Week 3 PM (2018) from 34:00 until the break about time preference (4.1), and from 1:17:00 to 1:40:00 about finite horizon dynamic programming (4.2). You can read the whiteboard.
*The first two videos were not rendered correctly. I think they are fixed now.*- Homework: 4.2, 5.3, practice question 33.
- You can watch the Q&A session, and read the whiteboard.
- Errata:
- In the simple fixed point theorem proof, it should read "g(x*) = 0", not "g(0) = 0".

- Week 4
- Watch Economies (5.1). You can read the whiteboard.
- Watch Efficient allocations (5.2). You can read the whiteboard.
- Watch Equilibrium (5.3). You can read the whiteboard.
- Watch Model formulation. You can read the whiteboard.
- Watch First welfare theorem (5.5).
- Watch Walras law (5.4). You can read the whiteboard.
- Homework: 5.2, practice questions 4(i)-(v) and 6(i)-(v).
- Please come to the Q&A session at 2pm on Monday. You can watch the Q&A session.

- Week 3
- Watch Week 1 PM from 0:20 to 1:07, about isoquants (finishing 2.1) and quasiconcavity (finishing D). You can read the whiteboard.
- Watch Week 3 AM from 0:42 to 1:30, about convexity of upper envelopes, and increasing marginal cost (finishing 2.5). You can read the whiteboard.
- Watch Utility functions and the utility maximisation problem (3.1, 3.2) . You can read the whiteboard.
- Watch Income effects get in the way (3.3) . You can read the whiteboard.
- Watch Isolating the substitution effect (3.4) . You can read the whiteboard.
- Watch Slutsky equation (3.5) . You can read the whiteboard.
- Homework: 2.16, 3.1, 3.6, 3.7, and formulate the household's problem in practice question 14.
- Please come to the Q&A session at 2pm on Monday. You can watch the Q&A session.

- Week 2
- Watch Comparative statics (finishing 2.3). You can read the whiteboard.
- Watch Dynamic programming (2.4). You can read the whiteboard.
- Watch Constrained envelope theorem (starting 2.5). You can read the whiteboard.
- Please come to the Q&A session at 2pm on Monday. You can watch the Q&A session.
- Homework: 2.10, 2.11, 2.12, 2.5 (not 2.15).

- Week 1
- Optional: watch Naive Set Theory (B1, B2, B3) and Naive Set Theory (B4, B5, B6), which will help you understand the notation in the course. Note: these videos were primarily designed for other courses about proofs (including Mathematical Microeconomics 1), but I think many students will find these videos helpful. You can read the first and second whiteboard.
- Watch Production functions 1 (2.1). You can read the whiteboard.
- Watch Concave production functions (D and 2.1). You can read the whiteboard.
- Watch The firm's problem (2.2). You can read the whiteboard. Note: this lecture includes lots of non-examinable material about the chain rule and the implicit function theorem.
- Watch The envelope theorem (2.3). You can read the whiteboard.
- Watch the Q&A session if you missed it. The first few minutes are missing.
- Homework: 2.1, 2.2, 2.6, 2.7, 2.8, 2.9.
- Errata:
- In the last step of the chain rule proof of the envelope theorem (minute 26), the partial derivative should be with respect to a, not b.
- In the lazy decision maker proof of the envelope theorem, I sometimes confused Rupert Murdoch's sons, Lachlan and James. Only James is relevant to the proof.

- If you want to learn more mathematics, you can take Mathematical Microeconomics 1 instead.

## Assessment

Details on the assessment (including the marking criteria) are included in the practice question file. Two students kindly donated their marked exam scripts in 2017-8. Note that the December and May exams are marked on the same scale.

## Extra Reference

Some students like an extra reference, although it is unnecessary. I will only test knowledge from my notes. The references below are also available as a clickable reference list via the library.

Material marked with a star in the notes will only be tested in bonus questions; it is possible to get a distinction in the class without learning the starred material. My notes are closer to Varian and Kreps than MWG, but quite different from all of them. Ambitious students who would like a strong background in mathematics might want to read Maxwell Rosenlicht's (1968) "Introduction to Analysis" or Luenberger's (1969) "Optimization by Vector Space Methods". Angel de la Fuente's (2000) "Mathematical Methods and Models for Economists" is also helpful.

MWG means Mas-Colell, Whinston and Green's (1995) "Microeconomic Theory". V means Varian's (1992) "Microeconomic Analysis". K means Kreps' (1990) "A Course in Microeconomic Theory". KK means Kreps' (2013) "Microeconomic Foundations 1: Choice and Competitive Markets". SL means Stokey and Lucas (1989), "Recursive Methods in Economic Dynamics". Debreu (1960) is Topological methods in cardinal utility theory.

- Introduction
- Production
- Production Functions
*See: V1, MWG5, K7.1* - Profit Maximization
*See: V2, MWG5, K7.2* - Upper Envelopes and Value Functions
*See: V3, SL4, MWG5, K7.2* - Cost Functions and Dynamic Programming
*See: V4, SL4, MWG5, K7.3, K.A.2* - Upper Envelopes with Constraints
*See: V5, SL4, MWG5, K7.3*

- Production Functions
- Consumption
- Utility Functions
*See: V7, MWG3, K2.1* - Utility Maximization
*See: V7, MWG3, K2.2* - Consumerâ€™s Value and Policy Functions
*See: V7, MWG3, K2.2, K2.3* - Expenditure Function and Policy Functions
*See: V7, MWG3, K2.2, K2.3* - Slutsky Decomposition
*See: V8, MWG3, K2.3*

- Utility Functions
- Time
- Time Preference
*See: Debreu (1960), V19, SL4, SL5, MWG20, KK2.5*

- Time Preference
- Equilibrium
- Economies
*See V17, V18, V19, MWG16, K6.1, K6.2* - Efficient Allocations
*See V17, V18, V19, MWG16, MWG22, K5.2* - Equilibrium
*See V17, V18, V19, MWG16, K6.1* - Characterising Equilibria
*See V17, MWG15, MWG16, MWG20, K2.2* - Efficiency of Equilibria
*See V17, MWG16, K6.3* - *Existence of Equilibria
*See V17, MWG17, K6.4* - Implementation of Efficient Allocations
*See V17, MWG16, K6.3*

- Economies