You'd need to show paper bags are less impactful than plastic before knowing whether to recommend them.
Paper bags also may see fewer reuses than plastic ones.
The question whether paper bags are more environmentally friendly than plastic ones is not an easy one to answer.
Most discussions on this I have read conclude you should bring your own bag, rather than single-use plastic or paper bags.
The city even recommends using them for yard waste and other compostables as the bags are perfectly biodegradable.