Fertility Projections in a European Context: A Survey of Current Practices among Statistical Agencies

Abstract

Projection studies have often focused on mortality and, more recently, migration. Fertility is less studied, although even small changes can have significant repercussions for the size and age structure of future populations. Across Europe, there is no consensus on how fertility is best projected. In this article, we identify different approaches used to project fertility among statistical agencies in Europe and provide an assessment of the different approaches according to the producers themselves. Data were collected using a mixed-method approach. First, European statistical agencies answered a questionnaire regarding fertility projection practices. Second, an in-depth review of select countries was performed. Most agencies combine formal models with expert opinion. While many attempt to maximise the use of relevant inputs, there is more variation in the detail of outputs, with some agencies unable to account for changing age patterns. In a context of limited resources, most are satisfied with their approaches, though some are assessing alternative methodologies to improve accuracy and increase transparency. This study highlights the diversity of approaches used in fertility projections across Europe. Such knowledge may be useful to statistical agencies as they consider, test and implement different approaches, perhaps in collaboration with other agencies and the wider scientific community.

Differences in time-critical interventions and radiological examinations between adult and older trauma patients: A national register-based study

“…Norway has a population of 5.4 million people, of which approximately 16.5% are 65 years or older. 15 The health care system is publicly funded, and a nationwide inclusive trauma system is implemented, describing national field triage criteria (Fig. 1) and uniform requirements to all prehospital services and hospitals.…”

Assessing the Accuracy of National Population Projections

“…It is perhaps unfortunate, therefore, that most agencies only evaluate the accuracy of their short-term projections, that the evaluations are mostly informal and only performed prior to the production of a new round of projections. Indeed, few agencies regularly report the accuracy of their past projections to users (Gleditsch et al 2021a).…”

“…When the following year's population has been calculated, it is used as the basis for calculating the population the year after. The cohort-component method is a common method for projecting populations and is used by most agencies that project populations at a national or international level (Gleditsch et al 2021a). Most of the assumptions that are used in the cohort-component method are stated as rates, probabilities or proportions by sex and one-year age groups.…”

“…Two notable exceptions include Texmon and Keilman (1991) and Rogne (2016), the latter of which evaluated the accuracy of the projections made between 1996 and 2014. According to a recent survey of national statistical offices, the situation in other European contexts appears to be no better (Gleditsch et al 2021a).…”

Preface

“…The first four articles in this Special Issue deal with fertility and mortality in the context of their role in the population estimates and projections. To start with, Folkman Gleditsch et al (2021) offer a comprehensive overview of the way fertility assumptions are being treated and set in (mostly national level) population projections across Europe. The article reveals a diversity of approaches, typically based on a mix of formal modelling and expert input, but persisting in their use of variants to depict the future uncertainty, despite recent developments, for example in the area of stochastic forecasting.…”