Title:
Overview of the Centre for Mathematical Social Sciences

Speaker:
Mark Wilson, Computer Science and Centre for Mathematical Social Sciences (accompanied by Valery Pavlov)

Abstract:
The Centre for Mathematical Social Sciences at the University of Auckland is sometimes confused with COMPASS by outsiders. Although our structure, research methods and levels of funding have been quite different, it does seem that more collaboration could be explored.
I will give a quick overview of CMSS and discuss a few current research projects.

Date, Time, Venue: Friday September 12, 1-2, COMPASS meeting room (second floor, Fale Pacifika building)

Speaker: Nina Anchugina
Affiliation: PhD student, Department of Mathematics
Title: Evaluating Long-Term Investment Projects: What Should The Discounting Method Be?
Date: Wednesday, 27 Aug 2014
Time: 4:00 pm
Location: CAG17/114-G17 (Commerce A)

Increasingly today there is a necessity to evaluate projects, policies and activities, whose consequences will be spread over a long period of time.

Projects are usually analysed by converting the future values into present values by attaching some weight to each period; this procedure is known as discounting. Several methods of discounting have been developed but a universal one does not exist. The choice of discounting method, however, may be vital for deciding whether a certain project should be implemented or not. The question is: Which method of discounting should be used when evaluating long-term public projects?

In this talk we will firstly consider two main types of discounting, namely exponential and hyperbolic discounting, their functional forms, properties and implications. I will provide an example which illustrates how the choice of discounting method appears to be crucial for making a decision. Secondly, we will analyse an appropriate social discount function for a public project implied by an aggregation of the individual discount functions. Finally, we will investigate the situation when there is an uncertainty about discount rates for exponential discounting, which is a common case for long-term projects. I will also present some new results on the choice of a discount rate of the hyperbolic discounting when there is uncertainty about future rates .

Speaker: Golbon Zakeri
Affiliation: UoA Engineering Science
Title: Electricity market modelling, economics and analytics
Date: Wednesday, 20 Aug 2014
Time: 4:00 pm
Location: CAG17/114-G17 (Commerce A)

Over the past 2 decades there has been a major shift to meet the electricity needs of various countries and jurisdictions through markets. We will start by describing issues common to the vast majority of electricity systems and reasons that rationalised the move to electricity markets in developed countries. We will then discuss issues that arise from a transition to an electricity market with a particular focus on the NZ electricity market. This is a rich source of mathematical modelling, economics and analytics problems. We will lay out some of the more interesting problems that we have tackled and go in more depth to explore consequences of the introduction of renewables and our proposed solutions.

This talk is targeted towards members with varied backgrounds.

Everyone welcome!

Speaker: Jeremy Seligman
Affiliation: The University of Auckland (Philosophy)
Title: Secret tweets and network discovery
Date: Wednesday, 6 Aug 2014
Time: 5:00 pm
Location: Room 405, Engineering (403)

You are a secret agent with a secret S that you would like to transmit to a fellow agent a unobtrusively using a very public network like Twitter. Any information you tweet will be received by your followers on the network. You correctly assume that they will send the message on to their followers (retweet it) if and only if it does not conflict with any information they already possess. With luck, your message will be tweeted through the network until it eventually reaches a. Under what conditions is it possible for you to convey S to a in this way, without other agents in the network learning this information? Clearly,you cannot tweet S itself, but if, for example, a is the only agent to know that K then the message `if K then S’ may work, if there is a suitable path from you to a. To know whether you can succeed or not and what to tweet, you need to know something about the network and the information already possessed by the other agents. But you can learn something about this with a test tweet. If, for example, you know that you have two followers b and c and only b believes P and then you tweet the message `not P’ then if, after a certain length of time, someone tweets P to you, you know that there is a loop back to you via c. This talk will report on recent joint work on these and similar questions with Mostafa Raziebrahimsaraei.

Speaker: Matthew Ryan
Affiliation: Department of Economics, UoA
Title: Binary Stochastic Choice under Risk or Uncertainty
Date: Tuesday, 3 Jun 2014
Time: 5:00 pm
Location: Room 412, Science Centre (303)

Economists usually model choice as deterministic, via preference relations, though occasionally — and usually for econometric convenience — choice is allowed to be stochastic. Psychologists, on the other hand, typically model choice behaviour as intrinsically stochastic. In psychophysics, for example, it is common to model the probability of choosing one option over another (in a binary choice problem) as an increasing function of the difference in “utility” stimuli associated with the options. This is called a “strong utility representation” (SUP) for the binary choice probabilities.

These models of binary stochastic choice generate numerous interesting mathematical problems. This talk will introduce a small sample. The main focus will be on binary choice problems in which each option is a “lottery”, with risky or uncertain value. Given a specification of choice probabilities for all possible pairs of lotteries, under what conditions (on these probabilities) does there exist a SUP? What if we additionally require that the utility scale exhibit particular properties, such as linearity?

Speaker: Patrick Girard, Valery Pavlov and Mark Wilson
Affiliation: The University of Auckland
Title: Experimental study of influence in social networks
Date: Tuesday, 20 May 2014
Time: 5:00 pm
Location: OGGB level 0. DECIDE, The UoA Business Decision-Making Lab (formerly Lab 04

We present an overview of work in progress using the DECIDE lab (http://hfbeltran.wix.com/decide), part of a larger project on threshold models of influence. Our pilot study has yielded several interesting hypotheses for future investigation. We welcome audience suggestions for follow-up work.

Slides

Speaker:     Kerry Manson
Affiliation: The University of Auckland
Title:       Power Indices and their Real-World Application
Date:        Tuesday, 8 Apr 2014
Time:        5:00 pm
Location:    Room 412, Science Centre (303)

It has been recognised that standard, a priori power indices do not describe political power
well in many real-world situations. This lowers our ability to usefully incorporate the effects of
power distribution into political analyses. Methods of a posteriori power measurement which
take into account restrictions on the set of allowable coalitions are examined and developed. A
Hasse diagram representation of games is used to give a new method for adapting any a priori
Banzhaf index to a restricted coalition structure. A modified Banzhaf index is further analysed, and the
conditions for manipulation of this index by players are given.

The talk is based on Kerry’s Honours dissertation written in 2013.