Bad economics is when people make decisions that seem like a good idea at first, but end up causing more problems than they solve. It's kind of like when you want to eat all the candy in the house because it tastes good, but then you feel sick afterwards.
For example, let's say you have a lemonade stand and you charge too much money for your lemonade. People might not want to buy it because it's too expensive, and you won't make any money. This is bad economics because you're not making the best decision for your business.
Another example is when a government spends too much money on things they don't need, like building a big statue when there are people in the country who don't have enough food to eat. This is bad economics because the government is spending money on something that's not really helping anyone, instead of using that money to help people who are struggling.
So, bad economics is basically when people or governments make choices that don't make sense in the long run and end up causing more harm than good. It's important to think carefully about the choices we make and how they will affect others.