One must remember two things when reading this from Thomas Jefferson. First, the word "economy" didn't exist in 1808. Second, Jefferson is specifically naming a primary function of "capitalism", which like the word "economy", never existed over 200 years ago. It is also interesting to point out Adam Smith's understanding of what was capitalism or the free-market. In The Wealth of Nations, Smith uses the words "a system of perfect liberty" to describe what is now known as capitalism or the free-market.
This advice which is given by Thomas Jefferson over 200 years ago holds the same meaning in today's present times. What he is observing is essentially government intervention of the free-market by the means of government ownership. Jefferson understood, as did Smith, that "a system of perfect liberty" would provide the best price for the consumer because capitalism allows competition amongst industries creating innovation and ultimately driving down prices.
If Thomas Jefferson where amongst us today he would probably think two things about our current situation. One, he would think, "The sacred flame of Liberty has been distinguished." Two, he would think, "I specifically warned you how our republic will erode and you never listened...".
When Thomas Jefferson wrote this he was generally speaking about the entire economy and not only the mines. Jefferson is right, when governments purchase a company, lets say any private owned car business, the private owner will alway operate a more efficient business than the government ever could. Government goods and services, in history, have always operated extremely poorly and inefficient compared to private goods and services. Just think about how long you have to sit waiting at the State Department to get something done! It is slow and inefficient all because it is owned by the government.
I brought this Thomas Jefferson quote because there has already been legislation passed that grants the Federal Government not only to reform the current healthcare market (system) but also to have power to regulate the healthcare market. The words "Healthcare Market" are interchangeable with the word "Mines" in the quote and it would still have the same effect as it would the mines. For anyone who believes universal healthcare is a good idea for the United States is gravely mistaken and are being completely ignorant of the laws of economics. I understand how people can believe universal healthcare, provided by our Federal Government, is good for our nation, the idea sounds so fair and simple. That is the trick though, the idea sounds so fair to all Americans and seems achievable, that it actually doesn't work and worst, it creates poorer healthcare goods and services. Healthcare is such a worry theses days because it was the government's fault, who originally began regulating healthcare many many years ago, that made healthcare prices so incredibly high that something had to be done or people would revolt.
Thomas Jefferson knew that government ownership of private property or the economy (socialism) would be a lethal gust of tyranny blown towards our Nation's Sacred Flame of Freedom and Liberty and knew that our prosperity, life, liberty, and the pursuit of happiness would only grow and influence countries around the world under "a system of perfect Liberty" (Capitalism/Free-Market).
We must restore that "system of perfect liberty" that Smith spoke upon to free the economy and allow true prosperity for the United States of America!