Back in 1958, as part of the infamous Great Leap Forward, Chinese dictator Mao Zedong introduced the ‘four pests campaign’. This campaign sought to greatly improve public hygiene through the eradication of common pests and sources of disease such as mosquitoes, flies, rats, and birds.

Rather than achieving this goal, however, the campaign (unsurprisingly) led to a huge imbalance of the Chinese ecosystem. Through the extermination of millions of sparrows (who the Chinese government believed were responsible for eating the seeds needed to grow grain), the population of locusts boomed without their predators.

Anyone who knows what a swarm of locusts generally do can probably guess what came next. They devoured so many of the crops needed to feed the human population that the great famine soon followed, causing the deaths of tens of millions of people. As a result of short-sighted policy making, the natural balance was altered to the point of mass deaths and suffering.

It is exactly this kind of action that French economist Frédéric Bastiat had warned against almost 200 years beforehand. Bastiat argued that the most crucial difference between a good economist and a bad one, was that the former took into account not only the immediate effects of an action (the seen), but was also able to predict the less blatantly obvious by-effects (the unseen). Had Mao taken into account the natural consequences of a greatly diminished population of predators, millions of deaths could have been avoided.

Of course, the four pests campaign is an extreme example of a failure to learn Bastiat’s lesson. Yet, policy makers across the world continue to make the same mistake of promoting an action without thinking about the unintended negative outcomes.

For instance, the recent proposal to impose a tax on red meat in order to promote healthier lifestyles. Once again, this an idea that entirely ignores the unseen consequences. The idea behind the tax is that red meat is known to be unhealthy. Therefore, we should make it more expensive so that people buy less of it, and thus become healthier. Simple.

They’re not fully wrong; people probably would eat less red meat if it became more expensive. Specifically, poor people would eat less red meat, since they are the ones who are to feel the effects of a price increase far more so. To the rich, an increase in the price of beef is a minor inconvenience. To the poor, it can mean going without.

Moreover, what will be the effects on the alternatives? It would be logical to expect that consumers would switch to products like poultry and fish to fill the gap once filled by beef and pork. Most people likely know that an increase in demand, in this way, is also very likely to increase the price. Not only would red meat become less affordable, but the ‘healthier’ alternatives as well.

In trying to promote a healthier lifestyle, such a policy would simply make life more difficult for the poorest few through raising the cost of that most basic necessity, food. Of course, this isn’t the first time the state has done this. Just look at the decision of the Scottish government to impose a price-floor on alcohol earlier this year.

Naturally, while the effects of meat tax, the price floor on booze, and the four pests are perhaps more obvious to foresee, it’s usually difficult to fully guess the unpredictable outcomes of a policy. The clue is in the word ‘unpredictable’. State meddling in this way often leads to negative side-effects that few could have seen coming.

Like the greatest movie ending in the history of 80’s movies, the only way to win may be not to play at all. Rather than risk the adverse, unforeseen events of nannying policies, people need to be left alone to make their own mistakes, and bear the consequences of their own mistakes, rather than those of the state.

Centrally planning without damaging other areas is nigh impossible, be it in economics, public health, or any other kind of policy making. Why, then, do we keep trying it?