For better examples of liberalism at work, on the international stage look at the nordic countries, and how they somehow manage to stay at the top of the world quality-of-life indexes, and domestically
The Nordic countries have significant advantages over most of the world: great access to natural resources, a relatively small, homogeneous, well educated population; limited border access (and much of that is trackless wilderness); little need to spend much on research or defense (they can just mooch off the USA and others), and so on. They can afford to experiment with liberal policies that might destroy other country's economies.
The nordic countries have had liberal politics for decades. That's not experimentation. That's established policy. Norway has great natural resource wealth with their oil reserves, but Sweden has a much more manufacturing & trade oriented economy, with several major private companies that play on the world stage such as Ericsson, SAAB, and IKEA. And somehow these corporations are wildly successful in a country known for high taxes.
Also, investment in education is a liberal policy known to benefit society immensely.
The Greek political mess is due to massive entitlement, which believe it or not has nothing to do with liberal politics.
I don't believe it. The vast majority of entitlements in the USA result from liberal policies. Why would Greece be any different? Conservatives believe in balanced budgets and not going into debt except under very special circumstances: in their worldview, running a government should be no different than running a home. or a farm, or a ranch, or a business, at least from a financial perspective. This viewpoint is why so many people that actually have to manage budgets, support conservative politics. Those who routinely over-spend their means support liberal politics.
Conservatives believe in destroying revenue sources, and then spending all the money they don't have on the military. Over the last few decades, the highest deficits have been with Republican presidents, and the last time we had a budget surplus was during Clinton's presidency. Conservatives might run the government like they do businesses, so it should come as no surprise that Donald Trump's corporations have filed for bankruptcy four times.
look at the policies of Minnesota, and specifically how Minnesota has fared economically since Dayton became governor, compared to how Wisconsin has done since Walker came
As Paul Tosto notes in his article at NPR news, "Essentially, Minnesota has an advantage over Wisconsin in key growth sectors — education, health services and professional and business services. (Those sectors have also driven U.S. job growth, as the Wall Street Journal reported recently.) Wisconsin has a bigger stake in manufacturing, which has been in steady decline for years as a jobs creator. The Great Recession accelerated those changes and Minnesota benefited.".
Hence, liberalism has nothing to do with Minnesota's economic success.
Investing in education and health services is a liberal policy. Also, Scott Walker's "open for business" tea party policies were supposed to attract large corporations and therefore result in job growth. This hasn't happened. Meanwhile, a focus on investing in education in Minnesota (not a major source of jobs itself - you can only have so many professors) has resulted in a well-educated workforce that big companies see as more valuable than rock-bottom tax rates. So yes, liberalism has had a positive effect on Minnesota's economy while conservatism has only hindered Wisconsin's.