Formula with text, good design?

Question

I have the following text in my align environment, but it does not look good. So what should I change in order to get a better design/output?

\documentclass[a4paper,     
        12pt,                               
        ]{scrreprt}
\usepackage{amsmath}
\begin{document}
\begin{align}
R_ {t+1}^{simple}=\frac{\text{(asset price at t+1) $ - $ (asset price at t)}}{\text{asset price at t}} \hspace*{0.5cm}r_{t+1}^{log}=ln \left( \frac{\text{asset price at t+1}} {\text{asset price at t}}\right) \hspace*{0.2cm}
\end{align}
\end{document}

Answer 1

I would

1. format textual superscripts with \textrm
2. use \ln instead of just ln (assuming this is a logarithm)
3. use equation instead of align for a single equation
4. define a variable for the asset price to reduce repeating text.

That gives:

\documentclass[a4paper,     
        12pt,                               
        ]{scrreprt}
\usepackage{amsmath}
\parindent0pt
\begin{document}
Old version:
\begin{align}
R_ {t+1}^{simple}=\frac{\text{(asset price at t+1) $ - $ (asset price at t)}}{\text{asset price at t}} \hspace*{0.5cm}r_{t+1}^{log}=ln \left( \frac{\text{asset price at t+1}} {\text{asset price at t}}\right) \hspace*{0.2cm}
\end{align}

New version:
\begin{equation}
  R_{t+1}^{\textrm{simple}} = \frac{P_{t+1}-P_t}{P_t}
  \qquad
  r_{t+1}^{\textrm{log}} = \ln \left(\frac{P_{t+1}} {P_t}\right),
\end{equation}
where  $P_t$ is the asset price at $t$.
\end{document}

and looks like this:

Answer 2

You should be more careful with what is math and what is text. I would do something like this

R_ {t+1}^{\textup{simple}}=
  \frac{\text{(asset price at $t+1$) $ - $ (asset price at $t$)}}
    {\text{asset price at $t$}} 
\hspace*{0.5cm}
r_{t+1}^{\textup{log}}= 
\operatorname{ln} \left( 
  \frac{\text{asset price at $t+1$}} 
  {\text{asset price at $t$}}
\right)

Now all the t should look alike. I don't see the point in the last hspace