Changes in the Distribution of Wealth Between 1989 and 2004

Changes in the Distribution of Wealth Between 1989 and 2004:

Tom Bozzo of Marginal Utility let me know about this Fed report on changes in the distribution of wealth and net worth from 1989 to 2004. Here's the abstract plus several graphs constructed from tables in the report. The first graph shows, for example, that the percentage of net worth held by the bottom half of the distribution was 2.5% (see table 5 in the report):

Currents and Undercurrents: Changes in the Distribution of Wealth, 1989–2004, by Arthur B. Kennickell Senior Economist and Project Director, Survey of Consumer Finances, Federal Reserve Board: Abstract This paper considers changes in the distribution of the wealth of U.S. families over the 1989–2004 period ... Real net worth grew broadly over this period. At the same time, there are indications that wealth became more concentrated, but the result does not hold unambiguously across a set of plausible measures. ... Graphical analysis suggests that there was a shift in favor of the top of the distribution, while for the broad middle of the distribution increases were about in proportion to earlier wealth. Within this period, there are other interesting patterns. For example, from 1992 to 2004 the wealth share of the least wealthy half of the population fell significantly to 2.5 percent of total wealth. ... The paper also presents some information on underlying factors that may explain a part of the distribution of wealth, including capital gains, saving behavior and income, inheritances, and other factors. There are two special topic sections in the paper. The first presents information on the distributions of wealth of African American and Hispanic families. The second presents information on the use of debt across the distribution of wealth.

As a sample of what's in the report, here are some of the tables in graphical form. First, here's a picture of the proportion of total net worth held by net worth percentile groups. This shows, for example, that the percentage of net worth held by people in the 99th-100th percentile group is slightly larger than the percentage held by the 50th-90th percentile group (click on graphs to bring up larger versions):
Next, this is the dollar value of net worth for various percentile groups of the net worth distribution:
Here is the percentage distribution of wealth across income classes. There are two versions, the one in color and one in black and white that shows the changes with better contrast:


Here's a look at the Gini Coefficent:
And finally, the distribution of the age of the family head by wealth (not net worth) group for 1989 and 2004:


The wealthier are older in 2004. There's a lot more in the report, including an analysis of sources in the changes in the wealth and net worth distributions. The paper looks at changes in capital gains, saving behavior, income, inheritances, debt, demographics, and other factors to explain shifts in the wealth and net worth distributions and finds that income, saving behavior, capital gains, and inheritances all play a role in the explanation.

A Clinical and Economic Analysis of Emergency Physician-Performed Ultrasonography in the Setting of Cholecystitis


The aim of this study was to evaluate a group of emergency physicians with Registered Diagnostic Medical Sonographer (RDMS) certification and fellowship training who utilize their ultrasound diagnosis in routine clinical care. While this level of training is likely to be higher than what should be required of most emergency physicians for routine focused ultrasonography, it is an ideal population to evaluate the potential for emergency physicians with a competency in ultrasound. Cholecystitis was chosen as the ultrasound study to investigate because it is a common disease process that presents emergently, is largely reliant on radiological diagnosis, and benefits from expedient management. In the 25 positive cases where a positive ED ultrasound was performed, a further radiological study followed in 86% of the cases. This study asks the question ‘how much would have been saved if these tests were not performed’?

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Computing in Economics

Here are the Lecture Notes, Slides and Handouts for the Course the Spring at the New School, taught by Myself, Rudi von Arnim, and Markus Schneider.


Download the Course Outline [.pdf]

Lecture One, Feb 2, 2006

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Lecture Two, Feb 16, 2006

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Lecture Three March 2, 2006

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Lecture Four--Rudi von Arnim

Lecture Five--Rudi von Arnim

Lecture Six April 4, 2006

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Recent Papers

Technical Reports for the Digital Enterprise Research Institute

Comparative Study of Electronic Market Efficiency

Digital Approaches to Economic Modeling

Papers on Methodology in Economics

Hedgehog Logic in Econometric Methodology, Student Economic Review, 2001

Economics and the Natural Science Method, Trinity Economic Papers, 2003, with F. O'Toole,

Technical Papers

Search and Selection in the Goodwin Growth Model, New School Working Paper Series

Subgame perfection in Semantic Web Services, XII International Con-
ference on Computing (CIC, 2004). Mexico City, Mexico. October 13-
15, 2004, with Juan Gomez

Book Reviews


Also available at ScienceDirect Here.

CTYI Game Theory Course


Game theory is the study of strategic interactions. This course is about asking what happens when people or things with different incentives or motivations interact \textit{against} one another to achieve their own best outcome. It has become the underpinning of evolutionary theory, economics, business processes, international relations and is the subject of major motion pictures, like `A Beautiful Mind'. In this course we will discover the laws underpinning every game and study specific examples of different types of games taken using examples from literature, the movies, board games, economics, molecular biology, international politics, business studies, dating, game shows, government funding opportunities and, of all things, fuel injection mechanisms in cars and the songs of the Dunes in the Sahel. Students who like mathematics will enjoy the course, and those who are less adept at maths but who enjoy playing constructively will benefit from taking this course.


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Course Outline Ver 0.2.pdf

Search and Selection in the Goodwin Growth Model


The Goodwin growth model is a particular dynamical system exhibiting limit cycle behaviour. I wish to add a measure of search and selection into the basic model by adapting one of the parameters of the model to be affected by an operator, such that the search process itself is a function of the relative slackness of the labour market summarised by the Phillips curve relationship modelled within the Goodwin model, and a new operator defined below, following Kauffman (1993) NK model of search and selection along fitness landscapes. The results of simulations show simply that the dynamics of the augmented Goodwin economy are essentially unchanged, though the search process itself is determined more by the macro-dynamics than the microeconomic conditions imposed on the actors in the system by the ruggedness of the landscape.


Mathematica as a Foundation for Economic Analysis

Lecture notes for the Mathematica Course for the Newschool are here in mathematica notebook format and in .pdf format. The main set of notes is in .nb, as people may need access to some of the code I've written in the appendices for other things  they might like to do. The lecture notes are in .pdf because I think you should go through the tedium of typing the functions in to learn the syntax, as opposed to just shift-entering your way through a notebook in 10 seconds and not learning anything about the system

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