Thank you all for your kind and encouraging comments, both for the situation and for my writing. Clearly this is a situation you all have thought about. I tried to respond in the comments section, but it got too long, so here is an additional post.
I share with edj a tendency to feel bad about whatever I’ve done, so I have learned to have a policy for situations like this, and then stick to the policy. Then at least I have the comfort of consistency. I debated for a long time whether it was right to give to beggars: wouldn’t they misuse the money? Probably. Jesus said “Give to whoever asks of you,” certainly one of his more troubling commands. The rabbis, addressing suspicion of beggars, said the only verification necessary for a person’s poverty is if he asks for money. Our great spiritual traditions have taught me that I need to cultivate a generosity of soul without reference to other people’s behavior. At some level, it’s not about them; it’s about the kind of person I want to be.
I start with a simple assumption of human dignity by only giving what is asked. I don’t like being duped, and I try to encourage honesty by expecting it. If someone begs for money, I will give them the pocket change I have handy. If they ask for food, I will give them food if I have it. If they ask for work, I will assume they really want to work and I will try to find some for them. I don’t let a request for work become a pretense for begging. Work has dignity, and I give people a chance at that dignity. Asking for food won’t get money from me. And nothing makes me angrier than a beggar saying, “Can I borrow a dollar?” I hate the disrespect of that refusal to admit the truth of the situation.
I don’t try to control what people spend money on. Larger organizations need to do this, obviously, but I’m just an ordinary person giving away a few bucks, and I am suspicious of my own desire to control people. I understand if you all choose otherwise, but in the giving that occurs in the brief contact of strangers, I give up control.
Thanks to Smoochy for his encouragement not to worry and his strong response to the importance of our actions. Can you tell he’s a new daddy to a brand new son? May God spare our children the life that comes with such foolish actions. I try not to worry too much. My sister tells me that our peaceful lives include a duty of gratitude for that peace. We owe it to those who have given it to us to live contentedly with it. So I try not to destroy my own peace by worrying about things that haven’t happened yet. Sometimes at night it gets difficult.
To KJ’s Muse, I think we are using different definitions of desperate. Alan has nothing. If he is willing to spend a whole afternoon earning $20, his life would actually be improved by a dead-end, minimum wage job, the sort of thing no educated person would consider. It would bring him more money than the sporadic things he could do for me.
If you haven’t read Helene’s comment yet, please do. She is dear to me in Real Life, and is one of the most generous people I know. Whatever she says on the subject is worth listening to.

It’s not often that I disagree with you, Mrs Mitchell, but in this case, I very much do. As a Christian, I think one should care about and help ones family, friends and neighbours, and the people in the community. I don’t think you have obligations to begging strangers, who come to your home. Statistics show that you endanger your family if you get involved like this. It’s odd that many criminals will sooner pick their victims among those who show them trust, as you did, than among people who turn them away. By some twisted logic, they will claim that you’re partly responsible for any misdeed. For showing them trust. To keep the little self-respect they have left, they have to think that you did it for yourself. To feel good, to show off, to enjoy a little schadenfreude (‘gloat’ in English?), to mess with them, whatever. I’ve learned that many American ‘outcasts’ are either mentally retarded or mentally ill because of the underdeveloped social system. They are even more unpredictable. Working for its enlargement would be of much more help and much less dangerous.
I think Jesus speaks to the heart. When he succeeds, our intellect must decide what is best. I don’t think it’s possible to say if you helped the man or not. At least not with any probability that is worth the risk. I hope I haven’t offended you in any way, Mrs Mitchell. You did grade your neighbourhood’s safety a while back, which to a Dane is rather disturbing, because it isn’t much of a concern here. ‘Pretty safe’, I think you said, is as bad as it gets.