Journal article: Why are many large non-governmental organizations (NGOs) becoming multinational entities? What are the welfare implications of this integration of markets for development donations? To answer these questions, we build a simple two-country model with horizontally differentiated NGOs competing in fundraising. We find that NGOs become multinational if the economies of scale in fundraising are sufficiently large. In that case, national NGOs in the smaller country disappear, while some national NGOs remain in the larger country only if country sizes are sufficiently different. Social welfare is higher in the regime with multinationals than under autarky.