The Evolution of Employment and Unemployment in Australia

This paper poses two questions: why did the equilibrium rate of unemployment rise so much in the 1970s, and why does unemployment increase rapidly during recessions, but decrease so slowly in the subequent recovery, i.e. why is unemployment persistent? We find that equilibrium unemployment rose because of the economy’s inability to adjust to the adverse shocks of the time; employment contracted in some sectors but did not expand sufficiently in others. In answer to the second question, we find that the sources of persistence are different for men and women. Male unemployment has been persistent because, following a recession, employment is created in female dominated sectors, rather than the male dominated sectors which experienced the greatest decline in employment. Female unemployment has been persistent because the growth in the demand for female labour has been matched by the growth in its supply. Finally, we find that recessions appear to have a permanent effect on the sectoral composition of the economy; i.e., recessions are periods of accelerated structural change.

Income support and staying in school: what can we learn from Australia's AUSTUDY experiment?

In Australia, as in most industrialised countries, there has been a dramatic increase in unemployment rates over the last three decades. The teenage labour market, in particular, has undergone significant structural changes which have resulted in large increases in the rate of unemployment among teenagers. The proportion of children staying on at school past the minimum leaving age and higher-education participation rates have also been rising over this period. Despite this, the overall full-time education participation of Australian teenagers remains low compared with that in most other OECD nations.

The fossilized birth-death model for the analysis of stratigraphic range data under different speciation concepts

A birth-death-sampling model gives rise to phylogenetic trees with samples from the past and the present. Interpreting "birth" as branching speciation, "death" as extinction, and "sampling" as fossil preservation and recovery, this model -- also referred to as the fossilized birth-death (FBD) model -- gives rise to phylogenetic trees on extant and fossil samples. The model has been mathematically analyzed and successfully applied to a range of datasets on different taxonomic levels, such as penguins, plants, and insects. However, the current mathematical treatment of this model does not allow for a group of temporally distinct fossil specimens to be assigned to the same species. In this paper, we provide a general mathematical FBD modeling framework that explicitly takes "stratigraphic ranges" into account, with a stratigraphic range being defined as the lineage interval associated with a single species, ranging through time from the first to the last fossil appearance of the species. To assign a sequence of fossil samples in the phylogenetic tree to the same species, i.e., to specify a stratigraphic range, we need to define the mode of speciation. We provide expressions to account for three common speciation modes: budding (or asymmetric) speciation, bifurcating (or symmetric) speciation, and anagenetic speciation. Our equations allow for flexible joint Bayesian analysis of paleontological and neontological data. Furthermore, our framework is directly applicable to epidemiology, where a stratigraphic range is the observed duration of infection of a single patient, "birth" via budding is transmission, "death" is recovery, and "sampling" is sequencing the pathogen of a patient. Thus, we present a model that allows for incorporation of multiple observations through time from a single patient

Job-search Methods, Neighbourhood Effects and the Youth Labour Market

Survey data suggest that unemployed teenagers look for work in ways that differ significantly from the ways which proved successful for teenagers who found work. This paper examines what factors affect the way teenagers look for work in order to explain why we observe this behaviour. We find that the single most important characteristic for explaining the job-search method choices of Australian teenagers is whether they receive unemployment benefits. Receiving benefits increases the probability of teenagers using the government employment agency as the main job-search method by almost 20 percentage points, and decreases their probability of using direct methods (such as contacting employers or friends and relatives) or newspapers by around 10 percentage points each. Personal characteristics and family background are also important for understanding the job-search methods chosen by unemployed teenagers. Another interesting finding is that the local environment, especially the state of the local labour market, is important for explaining job-search method choice. Higher local unemployment rates decrease the probability that an unemployed teenager will use direct search methods, and increase the probability that they will use the government employment agency. These results may help to explain the recently documented evidence that unemployment has become increasingly concentrated in low-socioeconomic-status neighbourhoods (Gregory and Hunter 1995).job-search methods; unemployment; neighbourhood effects

Monetary Policy-making in the Presence of Knightian Uncertainty

This paper explores the extent to which Knightian uncertainty can explain features of interest rate paths observed in practice that are not generally replicated by models of optimal monetary policy. Interest rates tend to move in a sequence of steps in a given direction, or remain constant for some time, rather than experiencing the frequent reversals that commonly arise from optimal policy simulations. We categorise the types of uncertainty that have been explored to date in terms of the decision-making behaviour they imply. From this, we suggest a more intuitively appealing formulation of Knightian uncertainty than the one that has previously been used in the analysis of monetary policy. Within a very simple optimal control problem, we show that our preferred formalisation is consistent with interest rate paths with periods of no change. This suggests that the presence of Knightian uncertainty may explain some features of monetary policy-makers’ behaviour.Knightian uncertainty; monetary policy

Bayesian total evidence dating reveals the recent crown radiation of penguins

The total-evidence approach to divergence-time dating uses molecular and morphological data from extant and fossil species to infer phylogenetic relationships, species divergence times, and macroevolutionary parameters in a single coherent framework. Current model-based implementations of this approach lack an appropriate model for the tree describing the diversification and fossilization process and can produce estimates that lead to erroneous conclusions. We address this shortcoming by providing a total-evidence method implemented in a Bayesian framework. This approach uses a mechanistic tree prior to describe the underlying diversification process that generated the tree of extant and fossil taxa. Previous attempts to apply the total-evidence approach have used tree priors that do not account for the possibility that fossil samples may be direct ancestors of other samples. The fossilized birth-death (FBD) process explicitly models the diversification, fossilization, and sampling processes and naturally allows for sampled ancestors. This model was recently applied to estimate divergence times based on molecular data and fossil occurrence dates. We incorporate the FBD model and a model of morphological trait evolution into a Bayesian total-evidence approach to dating species phylogenies. We apply this method to extant and fossil penguins and show that the modern penguins radiated much more recently than has been previously estimated, with the basal divergence in the crown clade occurring at ~12.7 Ma and most splits leading to extant species occurring in the last 2 million years. Our results demonstrate that including stem-fossil diversity can greatly improve the estimates of the divergence times of crown taxa. The method is available in BEAST2 (v. 2.4) www.beast2.org with packages SA (v. at least 1.1.4) and morph-models (v. at least 1.0.4).Comment: 50 pages, 6 figure

An Exploration of Marginal Attachment to the Australian Labour Market

One of the key factors that affects the extent to which changes in labour demand affect other macroeconomic variables, such as wage inflation, is the degree of matching between potential employees and available jobs. The pool of potential employees is usually measured as the pool of unemployed workers. However, this ignores an important group of people who are not officially unemployed, but do represent potential labour supply the marginally attached workforce, which can be broadly defined as the people who are not currently in the labour force, but want to work and are available to take up employment. The aim of this paper is to examine the extent to which the labour market behaviour of marginally attached workers is similar to that of the unemployed. We use longitudinal data from the Survey of Employment and Unemployment Patterns (SEUP), which provides detailed information on the characteristics of individuals as well as their labour market experiences, to compare dynamic behaviour across labour market groups, for example, the probability of moving into employment. We find that in some respects the dynamic behaviour of the marginally attached is similar to that of the unemployed, but in others it is quite different. Accordingly, the most appropriate measure of labour supply depends on the policy question, and consequently a range of measures should be considered.dynamic behaviour; effective labour supply; marginal attachment; transition probability; unemployment

Youth education decisions and job-search behaviour in Australia.

This thesis uses Australian unit-record data to examine two important aspects of labour supply behaviour. The first part of this thesis examines the participation decisions of Australian teenagers. Traditionally, the decision of whether to complete school or enter the labour force has been explained using personal characteristics, such as age and gender, and family background characteristics, such as parents' education. Chapter 2 extends this framework to consider whether neighbourhood characteristics provide information about these participation decisions over and above personal and family background characteristics. The results suggest that neighbourhood effects are present. Also within this framework, Chapter 3 considers whether government policy initiatives, designed to increase the proportion of Australian teenagers completing high school, achieved this aim. Again, the results suggest that this extension increases our understanding of teenage participation decisions. The second part of this thesis investigates two aspects of job-search behaviour. Chapter 4 examines the factors that affect how teenagers look for work. An equilibrium search model is developed to explain why local labour market conditions may be important. The empirical analysis supports the model's implication that teenagers in high unemployment areas are more likely to use general search methods, such as a newspapers or employment agencies, which appear to be less successful on average. Chapter 5 considers whether reservation wage information helps to explain the unemployment duration of the individuals in a sample that covers a wider cross-section of the Australian labour market. Despite the importance of this variable in job-search models, it does not appear to explain unemployment duration experiences once background characteristics and previous labour market experience has been controlled for

How the U.S. Air Force Space Command Optimizes Long-Term Investment in Space Systems

Interfaces, 33, p.p. 1-14.United States Air Force Space Command spends billions of dollars each year acquiring and developing launch vehicles and space systems. The space systems in orbit must continually meet defensive and offensive requirements and remain interoperable over time. Space command can launch additional space systems only if it has a launch vehicle of sufficient capacity. Space planners using space and missile optimization analysis (SAMOA) consider a 24-year time horizon when determining which space assets and launch vehicles to fund and procure. A key tool which in SAMOA is an integer linear program called the space command optimizer of utility toolkit (SCOUT) that Space Command uses for long-range planning. SCOUT gives planner insight into the annual funding profiles needed to meet Space Command's acquisition goals. The 1999 portfolio of 74 systems will cost about #310 billion and includes systems that can lift satellites into orbit; yield information on space, surface, and subsurface events, activities, and threats; and destroy terrestrial, airborne, and space targets