The united nations has developed several fertility scenarios that attempt to look at world population growth by the year 2100. these scenarios ignore the concept of the demographic transition, which is likely to result in a surge in the population as death rates fall. it also overlooks the fact that many countries that have gone through the demographic transition will see only a slight population growth. the major implication for the developed countries in the latter case is due to an increased

Due to an increased "dependency ratio".

The dependency ratio is a measure demonstrating the quantity of dependents, from age zero to 14 and beyond 65, the aggregate populace, aged 15 to 64. It is likewise alluded to as the "total dependency ratio." In financial aspects, geology, demography and sociology the dependency ratio is an age-populace proportion of those ordinarily not in the working class.

what is the tax base for the sales tax?

it should be (usually ) 6%

the earth’s crust is broken into separate pieces called tectonic plates (fig. 7.14). recall that the crust is the solid, rocky, outer shell of the planet. it is composed of two distinctly different types of material: the less-dense continental crust and the more-dense oceanic crust. both types of crust rest atop solid, upper mantle material. the upper mantle, in turn, floats on a denser layer of lower mantle that is much like thick molten tar.

each tectonic plate is free-floating and can move independently. earthquakes and volcanoes are the direct result of the movement of tectonic plates at fault lines. the term fault is used to describe the boundary between tectonic plates. most of the earthquakes and volcanoes around the pacific ocean basin—a pattern known as the “ring of fire”—are due to the movement of tectonic plates in this region. other observable results of short-term plate movement include the gradual widening of the great rift lakes in eastern africa and the rising of the himalayan mountain range. the motion of plates can be described in four general patterns:

collision: when two continental plates are shoved together

subduction: when one plate plunges beneath another (fig. 7.15)

spreading: when two plates are pushed apart (fig. 7.15)

transform faulting: when two plates slide past each other (fig. 7.15)