修訂. | 0d43b5cf811042fa1d8bed99eb5818db0c7da366 |
---|---|
大小 | 3,531 bytes |
時間 | 2019-10-18 19:38:51 |
作者 | Lorenzo Isella |
Log Message | A small doc showing how to write multiline equations. |
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\title{Definition of Key Statistics for the EU27 FDI}
% \author{Lorenzo Isella}
\date{}
\begin{document}
\maketitle
% \abstract{
% We give the definitions of growth rate and we introduce the main
% formulas for the calculations of the composite growth rate along a
% multi-period time span. After illustrating the shortcomings inherent to
% a straightforward calculation of the
% growth rate of trade flows, we suggest a methodology to bypass these
% issues which borrows from the theory of measurement of investment returns.
% }
\section{Relation between EU28 and EU27 Statistics}
Hopefully this document will become soon obsolete due to EUROSTAT
adding the information we need.
We need to be able to calculate the investments involving the EU27
from/to the UK and the EU27 and the UK from/to the extra EU27.
We go step by step and we use the notation $X\to Y$ to mean
investments from country $X$ to country $Y$. I would like to avoid going through the
individual country, i.e. building up the EU27 as the sum of the
individual MS.
For clarity
\begin{equation}
EU27=EU28-UK
\end{equation}
and
\begin{equation}
extra\;\;EU27=extra\;\;EU28+UK
\end{equation}
By using the definitions in the case of investments of the EU27 to
country X I get
\begin{equation}\label{eu27-flow}
\boxed{EU27 {\to X}=EU28 {\to X}-UK {\to X}}
\end{equation}
so, once I have the investments of the EU28 and the UK to a country X,
I get the EU27 investments to that country just by subtraction.
We now define the investments of an entity X towards the extra
EU27. The extra EU27 consists of everything outside the EU28 plus the
UK, so as a consequence
\begin{equation}\label{extra-eu27}
\boxed{X {\to extra\;\;EU27}= X {\to extra\;\;EU28} + X {\to UK}}
\end{equation}
i.e. once I know the investment of a country X to the extra EU28 and
to the UK, I can obtain by a simple sum the investments of country X
to the extra EU27.
Let us apply this to the extra EU27 investments by the UK
\begin{align}
\boxed{UK\to extra\;\; EU27=} & UK \to extra\;\; EU28+UK\to UK= \nonumber \\
&\boxed{UK\to extra\;\; EU28}
\end{align}
since the investments of the UK inside the UK are not included in
the FDI statistics ($UK\to UK=0$).
In the case of FDI, it looks like the extra EU27 investments from the
UK came for free.
Finally, here are the investments of the
EU27 towards the extra EU27.
\begin{align}
&\boxed{EU27 {\to extra\;\; EU27}=} (EU28-UK)\to (extra\;\;EU28 +
UK) \nonumber \\
&=EU28\to extra\;\;EU28+EU28\to UK -UK\to extra\;\;EU28+ \nonumber \\
& -UK\to UK \nonumber \\
&=\boxed{EU28\to extra\;\;EU28+EU28\to UK -UK\to extra\;\;EU28}
\end{align}
So the investments of the EU27 to the UK can be expressed purely in
terms of the investments of the EU28 and the UK towards the UK and the
extra EU28.
% \begin{align*}
% % \begin{empheq}[box=\widefbox]{align}
% & \boxed{EU27 {\to extra\;\;EU27}} = \\
% & EU28\to extra\;\;EU28+EU28\to UK -UK\to extra\;\;EU28
% % \end{empheq}
% \end{align*}
\end{document}