# Working papers

IGIER fellows and affiliates publish books and articles in academic journals. Their current research projects are featured in the Working Paper series.

What explains the formation and decay of clusters of creativity? We match data on notable

individuals born in Europe between the XIth and the XIXth century with historical city data.

The production and attraction of creative talent is associated with city institutions that protected economic and political freedoms and promoted local autonomy. Instead, indicators of local economic conditions such as city size and real wages, do not predict creative clusters. We also show that famous creatives are spatially concentrated and clustered across disciplines, that their spatial mobility has remained stable over the centuries, and that creative clusters are persistent but less than population.

uential findings that, we argue, face serious identification problems. Thus, while banks with low capital can be an important source of aggregate inefficiency in the long run, their contribution to the severity of the great recession via capital misallocation was modest.

We study monotone, continuous, and quasiconcave functionals defifined over an M-space. We show that if g is also Clarke-Rockafellar differentiable at (*see below picture*) , then the closure of Greenberg- Pierskalla differentials at x coincides with the closed cone generated by the Clarke-Rockafellar differentials at x. Under the same assumptions, we show that the set of normalized Greenberg-Pierskalla differentials at x coincides with the closure of the set of normalized Clarke-Rockafellar differentials at x. As a corollary, we obtain a differential characterization of quasiconcavity a la Arrow and Enthoven (1961) for Clarke-Rockafellar differentiable functions.

Does welfare improve when firms are better informed about the state of the economy and can better coordinate their decisions? We address this question in an elementary business-cycle model that highlights how the dispersion of information can be the source of both nominal and real rigidity. Within this context we develop a taxonomy for how the social value of information depends on the two rigidities, on the sources of the business cycle, and on the conduct of monetary policy.

a Hahn-Banach Theorem for modules of this kind;

a topology on the f-algebra that has the special feature of coinciding with the norm topology when the algebra is a Banach algebra and with the strong order topology of Filipovic, Kupper, and Vogelpoth (2009), when the algebra of all random variables on a probability space is considered.

As a leading example, we study in some detail the duality of conditional Lp-spaces.

Maccheroni, Marinacci, and Rustichini [17], in an Anscombe-Aumann framework, axiomatically characterize preferences that are represented by the variational utility functional where u is a utility function on outcomes and c is an index of uncertainty aversion. In this paper, for a given variational preference, we study the class of functions c that represent V. Inter alia, we show that this set is fully characterized by a minimal and a maximal element, c* and d*. The function c*, also identified by Maccheroni, Marinacci, and Rustichini [17], fully characterizes the decision maker's attitude toward uncertainty, while the novel function d* characterizes the uncertainty perceived by the decision maker.

the proposal to legalize paying these bribes while increasing fines on accepting them.

We explore performance as regards corruption deterrence and public service provision. Costs of verifying reports make the scheme more effective against larger bribes and where institutions' quality is higher. A modified scheme, where immunity is conditional on reporting, addresses some key objections. The mechanism works better against more distortionary forms of corruption than harassment bribes, provided monetary rewards can compensate bribers for losing the object of the corrupt exchange. Results highlight strong complementarities with policies aimed at improving independence and accountability of law enforcers.

patterns of political representation and the identity of elected legislators? This paper uses an important electoral reform passed in 1912 in Italy to provide evidence on these questions. The reform trebled the electorate (from slightly less than three million to 8.650.000) leaving electoral rules and district boundaries unchanged. By exploiting differences in enfranchisement rates across electoral districts we identify the effect of franchise extension on various political outcomes. Enfranchisement increased the vote share of left-wing social reformers but had no impact on their parliamentary representation, no impact on parliamentary representation of aristocracy and traditional elites and no effect on political competition. We show that left-wing parties decreased their vote shares and were systematically defeated in key swing districts. We document elite's effort to minimize the political impact of the reform and, in particular, we show that the Vatican's secret involvement in the post-reform electoral campaign had a substantial impact on voting results, although formerly and newly enfranchised voters were equally affected. We relate our results to economic theories of democratization, which appear to be only partially compatible with our evidence.

exam performance affects their future exam performance. Our identification strategy exploits a natural experiment in a leading UK university where different departments have historically

different rules on the provision of feedback to their students. We find the provision of feedback has a positive effect on students' subsequent test scores: the mean impact corresponds to 13% of a standard deviation in test scores. The impact of feedback is stronger for more able students and for students who have less information to start with about the academic environment, while no subset of individuals is found to be discouraged by feedback. Our findings suggest that students have imperfect information on how their effort translates into test scores and that the provision of feedback might be a cost effective means to increase students' exam performance.