In the real economy, the investment process has both endogenous and exogenous determinations: the investment
realized by a firm or corporation may be made in their own residential or other non-residential economies and
investments in a country can have domestic or attracted sources. This aspect has major implications in specifying
the econometric models of investment, in general. The analysis of the impact of FDI on some of the P-SCEEC
economies, in a difficult period of deep restructuring and integration in UE emphasise the importance of the major
theoretical concepts and theories in deeply understanding the specific character of international investment
processes.
The micro-economic definitions emphasizes that FDI occurs when an individual or firm acquires controlling
interest in productive assets of another country (http://www.dictionaryofeconomics.com/) and the macro-economic
conceptualization underlines the FDI as a component of country's national financial accounts, being an investment of
foreign assets into domestic structures, equipment, and organizations (On–line dictionary Economics About, http://
economics.about.com/). The last FDI 2013 survey have used a simple and modern methodological definition, that
stipulates that FDI are the net inflows of investment to acquire a lasting management interest (10 percent or more of
voting stock) in an enterprise operating in an economy other than that of the investor, as the sum of equity capital,
reinvestment of earnings, other long-term capital, and short-term capital as shown in IMF Balance of Payments
Manual, 5th edition (BPM6).
A major group of classical FDI theories are based on the last century’s trade theories, from the absolute or
relative comparative advantage theories in simple or generalized scheme, to the theoretical model of commercial
gravitation, from the Heckscher-Ohlin theoretical model (Heckscher, 1919; Ohlin, 1933), to Leontief’s paradox
(Leontief, 1953), from the theory based on the Linder assumption (Linder, 1961), the location theory, the theory of
market imperfections (Hymer, 1976; Kindleberger, 1969; Caves, 1971), etc. Another class of theory have focused on
traditional approaches, from the theory of FDI, based on monopolistic advantage (Hymer, 1976), or non-availability
(Kravis, 1956), or technological gap (Posner, 1961), to the Uppsala theoretical model, or from the theory of
information dissemination (Rogers, 1962), to the well known eclectic theory or paradigm (Dunning, 1993), etc.; The
last of the classical group are constructed on the exogenous factorial diversity, from the behavioural theory of the
firm (Cyert and March, 1963; Aharoni, 1966), to the contingency theory, from the contract theory, to the theory of
scale economy, from the internalization theory (Buckley and Casson, 1976; Rugman, 2009), to the product life-cycle
theory (Vernon, 1966), and from the theory of firm growth (Penrose, 1959), to the transaction cost theory, etc.
It can be also conclusively noted that no investment theory is explanatorily single-factor and distinctively
delimited from all the older or more recent economic theories of foreign direct investment, as they are all, to a
smaller or larger extent, unexpected theoretical mixtures or original syntheses with multi-impact assessment. The
most complex example is the eclectic theory, or John Dunning’s OLI model that focuses on the paradigm of
eclecticity, i.e. an apparently new concept, which is in fact a mixture of previous concepts, a non-homogeneous
system of thought, with no original ideas, still taking over the significant ideas in various theories or approaches,
also synthesizing the microeconomic and the macroeconomic segments of the FDI theory, bringing together the
international trade theory and the theory of investment localization, and combining factors and arguments from the
theory of monopolistic advantage and internalisation theories.
The models of FDI phenomenon could be classified in five specific classes of econometric models: a) based on
the correlation: economic growth - FDI (Keynes, 1930; Clarke, 1995; Harrod-Domar, 1939,1946; Solow, 1956 etc.);
b) defined by the FDI economic conceptualization (Kindleberger, 1969; Calvet, 1981; Kojima, 1973; Aliber, 1970);
c) underlining the structure as major classical aspects (Leontief, 1953 etc.); d) emphasizing the eclectic, trans-, and
interdisciplinary FDI approach (eclectic models restructured continuously after R squared and major statistical tests
of the model validation, diversified by Stopford and Strange, 1991; Porter, 1992; Dunning, 1993); e) identifying
signal variables as endogenous factors like crises / recession signals or the country risk rating signal (Săvoiu, et al.,
2013).
From the crises / recession signals’ models the most important are based on signals offered by GDP, or growth
rates of GDP, or GDP / capita as an indicator of overall productivity in an economy (Kobrin, 1976; Nigh, 1986;
Grosse and Trevino, 1996; Wells and Wint, 2000) models based on correlation between business cycle, productivity
and FDI (Larudee and Koechlin, 1999; Wang and Wong, 2007), and the models able to measure the FDI correlated
with indicators of external trade, based on the export orientation of the host country or based on correlation of the 

exports with the growing demand (Jun and Singh, 1996; Rob and Vettas, 2003), etc.
The last but not the least category of models that includes also this paper’s models reunites with the models that
correlate different risks of instability and FDI like macroeconomic risk (Jinjarak, 2007), or with general political
risk’s models (Kobrin, 1976; Kim, 2010), or with the models restricted to the risk of ensuring fundamental political
human rights (Fallon, Cook and Billimoria, 2001), and finally with the models linking FDI with country risk based
on the specialized agencies’ rating as Euromoney and its Country Risk - ECR, the best known European agency,
Moody’s and its Country Risk -MCR, Fitch and its Country Risk - FCR, Standard & Poor’s and its Country Risk –S
& PCR, etc.( Săvoiu and Popa 2012a; Săvoiu and Popa, 2012b; Săvoiu, et al. 2013).