We investigate investment incentives in credence CSR under different market structures. In duopoly, for high enough market transparency the firms differentiate their product by one of them investing. In monopoly with two factories (given that, say, the firms merged), with high enough market transparency the monopolist invests in one plant, mimicking duopoly. However, the necessary market transparency is higher, so competition promotes investment. Moreover, we also show that when market transparency lacks product traceability, whenever the monopolist invests it is in both plants, but then  the required information regarding the technologies being used by the firm is even higher. Overall we find that the market pushes toward product differentiation, which is good and bad: there is usually some investment by a firm, but also some factory producing with the old dirty technology. Given the effect of competition on CSR, we conclude that 'green' competition policy must be nuanced, taking into account (or regulating) both transparency and traceability.