Taking a job, any job, should always increase a person's net income. Similarly, working more as opposed to working less should consistently do the same. Working several jobs should do the same as opposed to doing only one job or doing no job. This is not always the case, depending on taxation, subsidies, and other eases.
Basic income would be a good solution for such traps.
You would always make at least X money where X is large enough that it allows you to live but small enough to make most people not want to live like that. So, there would be no unemployment checks, just basic income. If you took the job as a farm worker, you would always get your earnings on top of the basic income.