I just wanted to share a few quotations from the Writings and bit about my personal understanding that might relate to basic income:
Abdu'l-Baha says:
"KNOW THAT JUSTICE consists in rendering to each his due. For example, when a workman labours from morning till evening, justice requires that he be paid his wage, but bounty consists in rewarding him even when he has done no work and expended no effort. So when you give alms to a poor man who has made no effort and done nothing for your benefit to deserve it, this is bounty. Thus, Christ besought forgiveness for those responsible for His death: This is called bounty." (Some Answered Questions)
This quote, along with others, I believe is explaining Baha'u'llah's teachings that each person should be paid their due, according to the works they have done (although there are many teachings that stress the wage gap should be much narrower). For those who do not work, it may not be just, but it is indeed merciful and bountiful to give them an income so they may live a decent life.
Baha'u'llah says:
"It is unlawful to beg, and it is forbidden to give to him who beggeth." (Kitab-i-Aqdas)
Individual Baha'is are not allowed to give to those who do not work for a living to make their wages. However, Abdu'l-Baha clarifies this point by adding:
" ...“mendicancy is forbidden and that giving charity to people who take up begging as their profession is also prohibited.” He further points out in that same Tablet: “The object is to uproot mendicancy altogether. However, if a person is incapable of earning a living, is stricken by dire poverty or becometh helpless, then it is incumbent on the wealthy or the Deputies to provide him with a monthly allowance for his subsistence … By ‘Deputies’ is meant the representatives of the people, that is to say the members of the House of Justice.”
The prohibition against giving charity to people who beg does not preclude individuals and Spiritual Assemblies from extending financial assistance to the poor and needy or from providing them with opportunities to acquire such skills as would enable them to earn a livelihood"
So, the House of Justice or the very wealthy (as long as there still are the extremely wealthy), should indeed make provisions for the poor to receive a wage of sorts. To me this intends to say that the government should be responsible for looking after these individuals, and that the burden should not fall upon individuals to give them money as they beg.
In this sense, my personal opinion is that the Baha'i teachings may indeed support the idea of a basic wage given in selective situations. However, as bchurchill stated, an economist would need to weigh in and analyze the theory from an economical (academic and industrial) point of view, in addition to the spiritual I have attempted to provide above. Additionally, my opinion should in no wise be taken as the official opinion of the Baha'i community at large.
P.S. If clarification is required as to who Abdu'l-Baha and the House of Justice are: http://www.bahai.org/beliefs/bahaullah-covenant/