The present value of population growth in the western world

Abstract In conventional steady-state growth theory with technical progress exogenous, faster population growth causes lower consumption. This conclusion has influenced national policies. With technical progress endogenous, however, higher population growth causes higher consumption. Steady-state equilibrium analysis is not appropriate for policy decisions, though. Rather, appropriate analysis compares two or more growth rates beginning from equal initial positions, with comparison of the present value of consumption streams per person. In the paper the supply of and demand for knowledge is first analysed and the most plausible technical progress functions are derived. Various population growth rates are then simulated with different specifications and parameters. With virtually every variant, faster population growth shows better consumption with discount rates up to between five and ten per cent above the long-run adjusted riskless rate. With pensions included in the analysis, faster population growth would seem even more beneficial. Even at very high discount rates, lower population growth rates imply present values only a little higher than those for higher population growth rates. The advantage is overwhelmingly with higher population growth in this growth-theoretic analysis.     

The mixed effects of income upon successive births may explain the convergence phenomenon

Summary This paper finds that an increment of income has a more positive (less negative) effect on the probability of a family having another child when it consists of relatively few children than of relatively many children. That is, within a group of people whose income is increased, the increase may be expected to influence the average family with no children or one child to increase family size, and to influence the average family that would otherwise have many children to have fewer. To put it another way, increased income reduces the variance of family size across families. This provides an explanation for the 'convergence' of American families to two to four children. The basis for these conclusions is a cross-sectional analysis of white women in the U.S. Census of 1960.     

A variability taxonomy to support automation decision-making for manufacturing processes

Abstract

Although many manual operations have been replaced by automation in the manufacturing domain in various industries, skilled operators still carry out critical manual tasks such as final assembly. The business case for automation in these areas is difficult to justify due to increased complexity and costs arising out of process variabilities associated with those tasks. The lack of understanding of process variability in automation design means that industrial automation often does not realize the full benefits at the first attempt, resulting in the need to spend additional resource and time, to fully realize the potential. This article describes a taxonomy of variability when considering the automation of manufacturing processes. Three industrial case studies were analyzed to develop the proposed taxonomy. The results obtained from the taxonomy are discussed with a further case study to demonstrate its value in supporting automation decision-making.     

The exponentiation formula of reliability and survival: Does it always hold?

In reliability and biometry, it is common practice to choose a failure model by first assessing the failure rate function subjectively, and then invoking the well known exponentiation formula. The derivation of this formula is based on the assumption that the underlying failure distribution be absolutely continuous. Thus, implicit in the above approach is the understanding that the selected failure distribution will be absolutely continuous. The purpose of this note is to point out that the absolute continuity may fail when the failure rate is assessed conditionally, and in particular when it is conditioned on certain types of covariates, called internal covariates. When such is the case, the exponentiation formula should not be used.     

A Regional Multiplier Approach to Estimating the Impact of Cash Transfers on the Market: The Case of Cash Transfers in Rural Malawi

This article analyses the impact on the local economy of an emergency cash–transfer programme in rural Malawi. The results are of interest, given the growing use of cash transfers as development aid as well as the increasing popularity of such transfers as a form of social protection across sub–Saharan Africa. It uses a form of social accounting matrix to show that there are widespread benefits for the regional economy as a whole (with multiplier estimates of 2.02 to 2.45), especially during the most ‘lean’ periods of the year, and for small farmers and small businesses in particular, as this is where poorer households' purchases are focused; education and health also benefit.     

Source Attribution of Food-Borne Zoonoses in New Zealand: A Modified Hald Model

A Bayesian approach was developed by Hald et al .^{( 1 )} to estimate the contribution of different food sources to the burden of human salmonellosis in Denmark. This article describes the development of several modifications that can be used to adapt the model to different countries and pathogens. Our modified Hald model has several advantages over the original approach, which include the introduction of uncertainty in the estimates of source prevalence and an improved strategy for identifiability. We have applied our modified model to the two major food-borne zoonoses in New Zealand, namely, campylobacteriosis and salmonellosis. Major challenges were the data quality for salmonellosis and the inclusion of environmental sources of campylobacteriosis. We conclude that by modifying the Hald model we have improved its identifiability, made it more applicable to countries with less intensive surveillance, and feasible for other pathogens, in particular with respect to the inclusion of nonfood sources. The wider application and better understanding of this approach is of particular importance due to the value of the model for decision making and risk management.     

Pathways to Collective Protest: Calculation, Identification, or Emotion? A Critical Analysis of the Role of Group-Based Anger in Social Movement Participation

The dual-pathway model of collective action proposes two motivational pathways to collective protest, one is based on cost–benefit calculations and another is based on collective identification . The present research examined the role of feelings of group-based anger as an additional path. Study 1, a field study in the context of students' protest in Germany ( N = 201), provided evidence for a unique effect of anger. Study 2, a laboratory experiment ( N = 182), examined the desire to release aggressive tension as a psychological process underlying this effect. As hypothesized, analyses confirmed that anger affected participants' willingness to protest only to the extent that this behavior provided the opportunity of cathartic reduction in aggressive tensions. Moreover, an experimental manipulation providing an alternative means to release tension reduced the relationship between anger and willingness to protest to nonsignificance. The implications of these findings for reconceptualizing the role of anger in collective protest are discussed.