Make formulas start at the same point

I would like to list a few formulas which I have done as following:

\documentclass{article}
\usepackage{amsmath}
\begin{document}

\begin{enumerate}
\item \textbf{Hommes and in 't Veld AR(1) model:}
\begin{align}
x_t = \frac{1}{R^*}(n_{1,t} \phi_1 + n_{2,t}\phi_2)x_{t-1} + \epsilon_t.
\end{align}
\item \textbf{Weak trend following AR(2) model:}
\begin{align}
x_t = \frac{1}{R^*}((n_{1,t} \phi_1 + 1.4n_{2,t})x_{t-1} - 0.4n_{2,t}x_{t-2}) + \epsilon_t.
\end{align}
\item \textbf{Strong trend following AR(2) model:}
\begin{align}
x_t = \frac{1}{R^*}((n_{1,t} \phi_1 + 2.3n_{2,t})x_{t-1} - 1.3n_{2,t}x_{t-2}) + \epsilon_t.
\end{align}
\item \textbf{General trend following AR(2) model:}
\begin{align}
x_t = \frac{1}{R^*}((n_{1,t} \phi_1 + (1+\phi_3)n_{2,t})x_{t-1} - \phi_3n_{2,t}x_{t-2}) + \epsilon_t.
\end{align}
\end{enumerate}
\end{document}

The problem is that I would like to let these x_t begin at the same point. Does anyone know how to achieve this?

You can make use of amsmath's \intertext. By default this will not allow page breaks within the align environment, but if necessary it can be made possible.

\documentclass{article}
\usepackage{amsmath}

\begin{document}
\begin{enumerate}
\item \textbf{Hommes and in 't Veld AR(1) model:}
\begin{align}
x_t &= \frac{1}{R^*}(n_{1,t} \phi_1 + n_{2,t}\phi_2)x_{t-1} + \epsilon_t.\\
\intertext{\item \textbf{Weak trend following AR(2) model:}}
x_t &= \frac{1}{R^*}((n_{1,t} \phi_1 + 1.4n_{2,t})x_{t-1} - 0.4n_{2,t}x_{t-2}) + \epsilon_t.\\
\intertext{\item \textbf{Strong trend following AR(2) model:}}
x_t &= \frac{1}{R^*}((n_{1,t} \phi_1 + 2.3n_{2,t})x_{t-1} - 1.3n_{2,t}x_{t-2}) + \epsilon_t.\\
\intertext{\item \textbf{General trend following AR(2) model:}}
x_t &= \frac{1}{R^*}((n_{1,t} \phi_1 + (1+\phi_3)n_{2,t})x_{t-1} - \phi_3n_{2,t}x_{t-2}) + \epsilon_t.
\end{align}
\end{enumerate}
\end{document} In this specific example you can also use aligned where I have defined the \Indent macro to allow you to control the indentation: Notes:

• As hooy commented, With this method you do not get the equation numbers.

Code:

\documentclass{article}
\usepackage{amsmath}

\newcommand*{\Indent}{\par\hspace*{1.0cm}}

\begin{document}

\begin{enumerate}
\item \textbf{Hommes and in 't Veld AR(1) model:}
\Indent\begin{aligned} x_t = \frac{1}{R^*}(n_{1,t} \phi_1 + n_{2,t}\phi_2)x_{t-1} + \epsilon_t. \end{aligned}
\item \textbf{Weak trend following AR(2) model:}
\Indent\begin{aligned} x_t = \frac{1}{R^*}((n_{1,t} \phi_1 + 1.4n_{2,t})x_{t-1} - 0.4n_{2,t}x_{t-2}) + \epsilon_t. \end{aligned}
\item \textbf{Strong trend following AR(2) model:}
\Indent\begin{aligned} x_t = \frac{1}{R^*}((n_{1,t} \phi_1 + 2.3n_{2,t})x_{t-1} - 1.3n_{2,t}x_{t-2}) + \epsilon_t. \end{aligned}
\item \textbf{General trend following AR(2) model:}
\Indent\begin{aligned} x_t = \frac{1}{R^*}((n_{1,t} \phi_1 + (1+\phi_3)n_{2,t})x_{t-1} - \phi_3n_{2,t}x_{t-2}) + \epsilon_t. \end{aligned}
\end{enumerate}
\end{document}
• One will lose the equation numbers, though, if they are necessary. – sodd Feb 16 '16 at 11:14
• @hooyL Good point... Have made a note of that, – Peter Grill Feb 16 '16 at 11:15