 And now, great moments in unintended consequences. Part one, frozen coins. The year 2008. The problem? People aren't switching to dollar coins, even though they're heavier. The solution? Allow the general public to purchase the coins at face value directly from the US Mint and cover the cost of shipping. Sounds like a great idea, with the best of intentions. What could possibly go wrong? It turns out, people like free stuff and some credit cards offer rewards. Customers realize they could charge thousands of dollars worth of coins and then immediately pay off the balance with those very same coins, earning loads of free airline miles. Eventually the Mint caught on, changed their rules and blocked suspicious buyers from further purchases. But not before many had jacked up their reward points banking free trips around the world. One frequent player is even said to have bought 800 grand in coins, helping him earn lifetime platinum elite status on American Airlines. Now that's a coin trick. Part two, crop drop. The year? 2021. The problem? Sri Lanka's farms aren't organic. The solution? An immediate nationwide ban on synthetic fertilizer and pesticides, which coincidentally saved Sri Lanka $400 million in annual subsidy costs while they wrestle with a deep financial crisis. Oh, right, maybe that was the real problem. Sounds like a great idea, with the best of intentions. What could possibly go wrong? Turns out, synthetic fertilizer and pesticides actually work. Six months after the presidential decree, Sri Lanka's biggest export, tea, was down 18% and rights production plunged 20%, forcing the once proudly self-sufficient country to import rice at a cost of $450 million. Due to public backlash, the government was forced to reverse their ban and pay out hundreds of millions to compensate farmers, deepening the country's economic crisis and fanning protests that led to the president's resignation and temporary exile. Rice noenja. Part three, wild mongoose chase. The year? 1883. The problem? Rats in Hawaii are damaging valuable sugar crops. The solution? Control the rooms by introducing a new predatory species, the small Indian mongoose. Sounds like, let's be honest, we all know where this is going. It turns out, rats are generally nocturnal while the small Indian mongoose is active during the day. So the two species rarely met. Lucky for the mongooses, mongoose, mongooses? Whatever, lucky for them, Hawaii is full of appetizing native wildlife, including sea turtle eggs and numerous species of endangered birds. With no natural predators, the mongoosan thrived. 100 years later, they remain a massive problem on many of the islands. But now hear me out. Maybe if we introduce cobras. Great moments and unintended consequences. Good intentions, bad results. Do you have an idea for a great moment and unintended consequences? Put it in the comments below. And cite your sources. What are we, Harvard?