Framed paragraph with double-line frame

Question

Regarding various ways but most requires rigorous settings to embed a paragraph of words in a box or a frame with double-line box, I try to use a single commend to acquire the effect.

However, just as the picture has shown, the "doublebox" command in fancybox fails to wrap the words into paragraph. As for the "framed" command, it doesn't provide a "double-line" frame but actually wraps the paragraph instead.

Is there another command or a slight modification to the current code to warp a paragraph into a doubled-line frame(box)?

\documentclass[11pt]{article}
\usepackage{fancybox,framed}
\begin{document}
\doublebox{Over the past twenty years, the study of industrial organization—the analysis of imperfectly competitive markets—has grown from a niche area of microeconomics to a key component of economics.}\\

\begin{framed}
Over the past twenty years, the study of industrial organization—the analysis of imperfectly competitive markets—has grown from a niche area of microeconomics to a key component of economics. 
\end{framed}
\end{document}

Answer 1

\documentclass[11pt]{article}
\usepackage{fancybox,framed}
\begin{document}
\doublebox{%
\begin{minipage}{4in}
Over the past twenty years, the study of industrial organization—the analysis of imperfectly competitive markets—has grown from a niche area of microeconomics to a key component of economics.
\end{minipage}}\\
\begin{framed}
Over the past twenty years, the study of industrial organization—the analysis of imperfectly competitive markets—has grown from a niche area of microeconomics to a key component of economics. 
\end{framed}
\end{document}

Answer 2

Here's a tcolorbox version (with 'minimal' options) and some example of usages

\documentclass[11pt]{article}
\usepackage[most]{tcolorbox}


\newtcolorbox{tcbdoublebox}[1][]{%
  enhanced jigsaw,
  sharp corners,
  colback=white,
  borderline={1pt}{-2pt}{black},
  fontupper={\setlength{\parindent}{20pt}},
  #1
}
\begin{document}


%\doublebox{Over the past twenty years, the study of industrial organization—the analysis of imperfectly competitive markets—has grown from a niche area of microeconomics to a key component of economics.}\\

\begin{tcbdoublebox}
Over the past twenty years, the study of industrial organization—the analysis of imperfectly competitive markets has grown from a niche area of microeconomics to a key component of economics. 
\end{tcbdoublebox}


\begin{tcbdoublebox}[drop shadow]
Over the past twenty years, the study of industrial organization—the analysis of imperfectly competitive markets has grown from a niche area of microeconomics to a key component of economics. 
\end{tcbdoublebox}


\begin{tcbdoublebox}[title={With a title}]
Over the past twenty years, the study of industrial organization—the analysis of imperfectly competitive markets has grown from a niche area of microeconomics to a key component of economics. 
\end{tcbdoublebox}

\begin{tcbdoublebox}[colback={white!40!yellow}]
Over the past twenty years, the study of industrial organization—the analysis of imperfectly competitive markets has grown from a niche area of microeconomics to a key component of economics. 
\end{tcbdoublebox}


\end{document}