Engel_Function.tex

\begin{figure}[H]
    \centering
    \begin{tikzpicture}[scale=.7, font=\large]
        % axes
        \tzaxes(10,10){$x_1$}{$x_2$}
        % budget lines
        \tzfn{8-\x}[0:8, line width=1pt]
        \tzfn{5-\x}[0:5, line width=1pt]
        \tzfn{2.5-\x}[0:2.5, line width=1pt]
        % budget line labels
        \tznode(-1,6){\large $B_{\bar{p},w''}$}[l]
        \tznode(-1,4){\large $B_{\bar{p},w'}$}[l]
        \tznode(-1,2){\large $B_{\bar{p},w}$}[l]
        \draw[->, line width = 0.7pt](-1,6)--(0.5, 7.3);
        \draw[->, line width = 0.7pt](-1,4)--(0.5, 4.3);
        \draw[->, line width = 0.7pt](-1,2)--(0.5, 1.7);
        % Engel curve
        \tznode(4.5,6){\large $E_{p}$}[ar]
        \tzcdot*(3,5)(2mm)
        \tzcdot*(2,3)(2mm)
        \tzcdot*(1,1.5)(2mm)
        \tznode(3.2,5){$x(\bar{p}, w'')$}[r]
        \tznode(2.2,3){$x(\bar{p}, w')$}[r]
        \tznode(1.2,1.5){$x(\bar{p}, w)$}[r]
        \tzbezier[blue,line width=1.5pt](0,0)(1,0.5)(1,1.5)
        \tzbezier[blue,line width=1.5pt](1,1.5)(1.2,3)(2,3)
        \tzbezier[blue,line width=1.5pt](2,3)(2,3.3)(3,5)
        \tzbezier[blue,line width=1.5pt](3,5)(4,5.5)(4.5,6)
    \end{tikzpicture}
\end{figure}