What is the fine-grained topic of the following text: This paper shows that financial frictions in the form of collateralized borrowing at the firm level (Kiyotaki and Moore, 1997) can give rise to convex adjustment costs at the aggregate level yet at the same time generate lumpiness in plant-level investment. Only return the topic.
Convex adjustment costs and lumpiness in plant-level investment due to collateralized borrowing at the firm level.