1) Overspill 2) Population 3) Too much population 1) Overspill 
Overpopulation occurs when a population of a species exceeds the carrying capacity of its ecological niche. Overpopulation is a function of the number of individuals compared to the relevant resources, such as the water and essential nutrients they need to survive. It can result from an increase in births, a decline in mortality rates, an increase...
(from the article `Germany`) West of the Elbe the basic problem was not landlessness but overpopulation. The aristocracy along the Rhine and the Danube was often willing to give ...
When a reduction in population size would increase output per head i.e. it is above the optimum population.
[n] - too much population
overpopulation An excessive population of an area to the point of overcrowding with a depletion of natural resources, or environmental deterioration.
overspill noun too much population
Too many people for the resources available in an area (such as food, land, and water). The consequences were first set out by English economist Thomas Malthus at the start of the population explosion. Although there is often a link between overpopulation and population density, high densities do not always result in overpopulation. In many countri...