Federal Institute for Population Research

Top news

Schulklasse beim Unterricht (refer to: Verbal or numerical? How report cards change parents' views of their children's school skills) | Source: © contrastwerkstatt / Adobe Stock

Press releaseVerbal or numerical? How report cards change parents' views of their children's school skills

A new study by BiB shows that most parents overestimate their children's school skills. Written assessments in report cards have little effect on this, whereas grades have a stronger impact on parents.

Miscellaneous PublicationsR programs for splitting abridged fertility data into a fine grid of ages using the quadratic optimization method

Michalski, Anatoli I.; Grigoriev, Pavel; Gorlishchev, Vasily P. (2018)

MPIDR Technical Report TR-2018-002. Rostock

Occasionally, it is necessary to split aggregated fertility data into a fine grid of ages. In this technical report, we present an application of the quadratic optimization (QO) method for splitting abridged fertility data. The QO approach allows us to split not only age-specific fertility rates, but also birth counts in cases in which population exposures are available. Unlike the existing methods, the QO algorithm simultaneously satisfies five criteria of the ‘ideal’ disaggregation method: 1) shape – the estimated fertility curves should be plausible and smooth; 2) fit – the predicted values should be as close as possible to the observed values; 3) non-negativity – only positive values should be returned for the birth-order data; 4) balance – the estimated five-year age group totals should match the input data; and 5) parity – the balance by parity must be maintained. The examples provided in this report demonstrate the simplicity, flexibility, and high degree of effectiveness of the proposed technique.