Finite domination and Novikov rings. Iterative approach

Suppose C is a bounded chain complex of finitely generated free modules over the Laurent polynomial ring L = R[x,1/x]. Then C is R-finitely dominated, ie, homotopy equivalent over R to a bounded chain complex of finitely generated projective R-modules, if and only if the two chain complexes C((x)) and C((1/x)) are acyclic, as has been proved by Ranicki. Here C((x)) is the tensor product over L of C with the Novikov ring R((x)) = R[[x]][1/x] (also known as the ring of formal Laurent series in x); similarly, C((1/x)) is the tensor product over L of C with the Novikov ring R((1/x)) = R[[1/x]][x]. In this paper, we prove a generalisation of this criterion which allows us to detect finite domination of bounded below chain complexes of projective modules over Laurent rings in several indeterminates.Comment: 15 pages; diagrams typeset with Paul Taylor's "diagrams" macro package. Version 2: clarified proof of main theorem, fixed minor typos; Version 3: expanded introduction, now 16 pages; Version 4: corrected mistake on functoriality of mapping tor

The gains from early intervention in Europe: Fiscal surveillance and fiscal planning using cash data

This paper does two things. First it examines the use of real time inter-annual cash data and the role of early interventions for improving the monitoring of national fiscal policies and the correction of fiscal indiscipline. Early warnings are important because they allow us to spread the necessary adjustments over time. Examples from Germany and Italy show that large corrections are often necessary early on to make adjustments later on acceptable and to keep debt ratios from escalating. There is a credibility issue here; we find the difference between front-loaded and back-loaded adjustment schemes is likely to be vital for the time consistency of fiscal policymaking. Second, without early interventions, the later deficit reductions typically double in size – meaning governments become subject to the excessive deficit procedure and significant improvement tests more often. Thus the budget savings from early intervention and the use of cash data are significant; in our examples they are similar in size to the operating budget of the department of housing and urban development in Germany. Similar results apply in other Eurozone countries. JEL Classification: E62, H50, H68additive vs slope adjustments, cash data, early warning, fiscal credibility, fiscal surveillance