Revenstein “law of Migration”: in 1880, Ernst Georg Ravenstein published “The law of migration in the
journal of the Statistical Society, which established the theory of human migration that sill forms the basis
for modern migration theories. It considered the implication of distance and type of migrant.

Lee (Push-Pull) model: is a model that explains the decision of migration to based on four factor,
characteristics of Origin, characteristics of Destination, Characteristics, Nature of intervening Obstacles,
and Nature of the people.

Gravity migration model (Karemera, Oguledo, & Davis, 2000) is derived from Newton’s law of gravity. It
measures the degree of interaction between two places. And it is based upon the idea that as the
importance of one or both of the location increases there will also be increase in the movement between
them. This model have been widely used in the empirical analysis of migration due to their relatively good
forecasting performance. But since it is based observations, it is considered that it cannot be confirmed
scientifically.

The spatial interaction model is a common deterministic model used in migration analysis based on Gravity
model. Where the migration between to origin i and destination d is proportional to the product of
populations at origin and destination and inversely proportional to the distance between them.

(Kunz, 1973) created the first universal topology of characterizing migrations and a seminal paper by
(Simini, González, Maritan, & Barabási, 2012) combined the lessons from scale-free networks with
previous migration models to yield a unified model of migration, suggesting that the gravity model
combined with the spatial model can give an accurate model of migration and indicate different ‘threshold
levels’ at which humans are triggered to move. Studying the interaction of two population groups
competing for one pathc of land, (Auger & Poggiale, 1996) found that migration is much faster social
phenomenon that population growth and people would have and a particular choice of density dependent
migrations leads to an aggregated competition model. In an attempt to view migration a lifecycle process,
(Ryan, Dooley, & Benson, 2008) propose a resource-based model for migration, but they specify that the
resources in this case must be understood as those fulfilling the needs of individuals – and they might
change over time so they must be monitored before, during and after migration. Already in (Borjas, 1989)
postulated that migration is an economically driven phenomenon and can be explained purely by the laws
of markets, attributing a net economic loss to the worsening conditions that would trigger the migration
and he also analyzed the impact of migrants on target countries’ economies – applied to Vietnamese
refugees in the US by (Montero, 1979) – while (Boyd, 1989) characterized migration mainly as a social
phenomenon, driven by family ties.

One of the most striking characteristics if the current Syrian refugee crisis is the seemingly dormant state
for 4 years (due to being largely underreported by the mainstream media and people fleeing at
comparably constant rates to today’s values into neighboring countries) and then a sudden intensification
of flows towards Europe in the past year. (Zolberg, 1989) suggested that due to globalization and
economic integration, labor outsourcing, migration will intensify in the next few decades – a prediction
that what spot on even without foreseeing the unpredictable social catastrophes in the Middle East or
Africa (Neumayer, 2005).

With the advent of many international organizations getting well-funded statistics departments, there
was a surge in the need of characterizing data streams. Therefore, many different definitions of a what
constitute of a refugee and what constitute a migrant appeared, oftentimes with the sole purpose of
presenting the refugee numbers in a ‘better light’ (Zetter, 2007).