I am divided on this issue, on one hand it make it easier to live on the margin. On the other hand it removes the incentive to stay on unemployment vs. getting a job that pays the same amount. Aka. 500$ / week makes anything under 30k a pay cut after commuting expenses, and anything under 40k a minimal increase.
To avoid that weird incentives gap the basic income should be unconditional, so without a means test. Regardless if they are unemployed or employed every citizen receives every week or month a mount of money. No questions asked. Any money you make from a job is just additional income.
The expectation is that people will want to work. Naturally a unconditional basic income will change things: Some will seek employment, others will start a business, and then there are the open source programmers. etc. Another advantage is that one could eliminate minimum wage.