# Aligning Math Equations around Single Equal Sign Across Several Pages with Text between Equations

I am writing an appendix to my paper in LaTeX Article class. I have dozen of equations and derivation there and I want to align all of them around a single equal (=) sign. Look at how I currently have them: Presently they are not aligned along the same equal sign. I want to align them and this should be effective not for just a few equations but for all dozens of expressions over several pages. I am aware that I could do it if it were for just a few equations with not much text in between but how to do it if you want to write a bunch of equations over several pages with text explanations in between them and you still want all those equations aligned around one equal sign? Here is my MWE:

\documentclass{article}
\usepackage{amsmath,amssymb}
\begin{document}
Given $K$, gross return on capital, ad wage can be computed as
\begin{align}
R^{K} & = \alpha K^{\alpha - 1} + 1 - \delta\\
W & = (1 - \alpha) Z K^{\alpha}
\end{align}
Using first order conditions for $D_{t+1}^{H}$ and $B_{t+1}^{R}$,  steady state interest rates can be determined as
\begin{align}
R^{D} & = \frac{1}{\beta}\\
R^{B} & = \gamma \frac{R^{K}}{1 + f^{R}} + (1 - \gamma) R^{D}
\end{align}
Given $R^{K}$, $K^{H}$ is determined by the Euler equation of the  household with respect to $K^{H}$
\begin{align}
R^{K} & = \frac{1}{\beta} \left( 1 + \eta^{H}\frac{K^{H}}{K} \right)\\
\frac{K^{H}}{K} & = \frac{1}{\eta^{H}} (\beta R^{K} - 1)
\end{align}
\end{document}

• Look up \intertext in the amsmath manual. The mathtools package also offers \shortintertext which has less vspace around it. Use those for the text lines and just one align env. Latex are allowed to break an align before intertext or shortintertext – daleif Dec 22 '19 at 10:25

You can simply use the \intertext command which allows to insert text in an align environment.

\documentclass{article}
\usepackage{amsmath}
\begin{document}
Given $K$, gross return on capital, ad wage can be computed as
\begin{align}
R^{K} & = \alpha K^{\alpha - 1} + 1 - \delta\\
W & = (1 - \alpha) Z K^{\alpha}
%
\intertext{Using first order conditions for $D_{t+1}^{H}$ and $B_{t+1}^{R}$,  steady state interest rates can be determined as}
%
R^{D} & = \frac{1}{\beta}\\
R^{B} & = \gamma \frac{R^{K}}{1 + f^{R}} + (1 - \gamma) R^{D}
%
\intertext{Given $R^{K}$, $K^{H}$ is determined by the Euler equation of the  household with respect to $K^{H}$}
%
R^{K} & = \frac{1}{\beta} \left( 1 + \eta^{H}\frac{K^{H}}{K} \right)\\
\frac{K^{H}}{K} & = \frac{1}{\eta^{H}} (\beta R^{K} - 1)
\end{align}
\end{document}