One of the central problems in migration measurement arises as a consequence of the different sources of migration data. Most information regarding migration is obtained from population censuses or population registers that report migration data for a given time interval. Another source of migration data is the sample survey which may be designed to provide information about both migrants and...

"This paper attempts to describe the nature of Zambia's demographic situation, which eventually led to the formulation of a national population policy; the policy instrument; and some of the measures necessary for the effective implementation of the policy....[The] situation is characterised by three dominant features: a high rate of natural increase, massive urbanisation, and wide variations ...

Abstract Numerous product quality scandals are caused by low-quality inputs. When input is not perfectly observed downstream firms, upstream firms often have moral hazard problems. If vertical integration does directly eliminate the problems, still improve quality? so, under which conditions? We find that given precision of monitoring technology used when level public very high or low, no incen...

The thermal field of the Gulf of Mexico (GoM) is analyzed from a comprehensive temperature-depth database of about 8500 Bottom Hole Temperatures and Reservoir Temperatures. Our stochastic analysis reveals a widespread, systematic sharp thermal gradient increase between 2500 and 4000 m. The analysis of the pressure regime indicates a systematic correlation between the pressure and temperature fi...