How to change the arrow length of a diagram using Tikz?

Question

I would like to change the arrow size of a diagram. I would like to have a small arrow. Looking at the code:

\begin{tikzpicture}[
every text node part/.style={align=center}, 
]
\node (a) at (0,0) {Economically Liberal States};
\node[below=of a] (b) {Free Trade Policies};
\node[below=of b] (c) {Protect and Support Industries};
\node[left=of a] (d) {Karl Polanyi};
\draw[->] (d.east)--(a.west);
\draw[->] (a.south)--(b.north);
\draw[->] (b.south)--(c.north);
\end{tikzpicture}

I got:

I would like to get an arrow length like this one:

Answer 1

Distance rather than the length.

\documentclass{article}

\usepackage{tikz}
\usetikzlibrary{positioning}


\begin{document}
\begin{tikzpicture}[
every text node part/.style={align=center}, node distance=0.3cm
]
\node (a) at (0,0) {Economically Liberal States};
\node[below=of a] (b) {Free Trade Policies};
\node[below=of b] (c) {Protect and Support Industries};
\node[left=of a] (d) {Karl Polanyi};
\draw[->] (d.east)--(a.west);
\draw[->] (a.south)--(b.north);
\draw[->] (b.south)--(c.north);
\end{tikzpicture}
\end{document}

Thanks to @TeXnician