Control Rights in Public-Private Partnership

This paper develops a theory of the allocation of authority between two parties that produce impure public goods. We show that the optimal allocation depends on technological factors, the parties' valuations of the goods produced, and the degree of impurity of these goods. When the degree of impurity is large, control rights should be given to the main investor, irrespective of preference considerations. There are some situations in which this allocation is optimal even if the degree of impurity is very low as long as one party's investment is more important than the other party's. If the parties' investments are of similar importance and the degree of impurity is large, shared authority is optimal with a greater share going to the low-valuation party. If the importance of the parties' investments is similar but the degree of impurity is neither large nor small, the low-valuation party should receive sole authority. We apply our results to a number of situations, including schools and child custody.

Control Rights in Complex Partnerships

This paper develops a theory of the allocation of authority between two players who are in a “complex” partnership, that is, a partnership which produces impure public goods. We show that the optimal allocation depends on technological factors, the parties’ valuations of the goods produced, and the degree of impurity of these goods. When the degree of impurity is large, control rights should be given to the main investor, irrespective of preference considerations. There are some situations in which this allocation is optimal even if the degree of impurity is very low as long as one party’s investment is more important than the other party’s. If the parties’ investments are of similar importance and the degree of impurity is large, shared authority is optimal with a greater share going to the low-valuation party. If the importance of the parties’ investments is similar but the degree of impurity is neither large nor small, the low-valuation party should receive sole authority. We analyze an extension in which side payments are infeasible. We check for robustness of our results in several dimensions, such as allowing for multiple parties or for joint authority, apply our results to interpret a number of complex partnerships, including those involving schools and child custody. JEL Codes: D02 ; D23 ; H41 ; L31Impure Public Goods ; Contractual Incompleteness ; Allocation of Authority ; Investment Incentives

Can Anyone be "The" One? Evidence on Mate Selection from Speed Dating

Marriage data show a strong degree of positive assortative mating along a variety of attributes. But since marriage is an equilibrium outcome, it is unclear whether positive sorting is the result of preferences rather than opportunities. We assess the relative importance of preferences and opportunities in dating behaviour, using unique data from a large commercial speed dating agency. While the speed dating design gives us a direct observation of individual preferences, the random allocation of participants across events generates an exogenous source of variation in opportunities and allows us to identify the role of opportunities separately from that of preferences. We find that both women and men equally value physical attributes, such as age and weight, and that there is positive sorting along age, height, and education. The role of individual preferences, however, is outplayed by that of opportunities. Along some attributes (such as occupation, height and smoking) opportunities explain almost all the estimated variation in demand. Along other attributes (such as age), the role of preferences is more substantial, but never dominant. Despite this, preferences have a part when we observe a match, i.e., when two individuals propose to one another.

Dating Preferences and Meeting Opportunities in Mate Choice Decisions

Much empirical evidence shows that female and male partners look alike along a variety of attributes. It is however unclear how this positive sorting comes about, because marriage is an equilibrium outcome arising from a process that entails searching, meeting and choosing one another. This study takes advantage of a unique data set to shed light on the forces driving choices at the earliest stage of a relationship. Both women and men value physical attributes, such as age and weight, and reveal that their dating choices are assortative along several traits. Importantly, meeting opportunities are found to have a substantial role in determining dating proposals.

Application of Fast-FWD for Accelerated Pavement Testing

Lo scopo di questa ricerca è quello di dimostrare come il Fast Falling Weight Deflectometer (FFWD), possa essere utilizzato come Accelerated Pavement Testing (APT). Dopo l'installazione di un sistema di raffreddamento che ha la funzione di impedire il surriscaldamento del motore, il Fast-FWD è stato in grado di funzionare senza interruzioni ad una velocità di 2600 colpi/ora, superando le aspettative di fabbricazione di produrre un carico ogni 1.5 secondi, ossia 2400 colpi/ora. La riduzione e il recupero del modulo degli strati legati possono essere simulati utilizzando una combinazione di modelli di danno e tixotropia, entrambi completi di relazioni che tengono conto del fenomeno di autoriparazione nel tempo. La rottura della pavimentazione, definita come una riduzione di oltre il 50% nel modulo dello strato di conglomerato, è stata raggiunta in meno di una settimana e più volte durante gli esperimenti. La rottura della pavimentazione definita dal raggiungimento di una deformazione permanente di 10-12 mm viene conseguita anch essa dopo poche applicazioni di carico. Anche in questo caso è da sottolineare come un dato modello può seguire precisamente l'evoluzione delle deformazioni permanenti misurate con l'incremento del numero di applicazioni. The principle aim of this research is to demonstrate how the Fast Falling Weight Deflectometer (FFWD), could be used for Accelerated Pavement Testing (APT). After the installation of the cooling system, that prevented the motor from overheating, the Fast-FWD was able to run without any interruptions at a rate of 2600 drops/hour, exceeding production expectations of producing one load every 1.5 seconds, that corresponds to 2400 drops/hour. The decrease and recovery of AC modulus could be simulated using a combination of models for damage and thixotropy, both supplemented by time based recovery models. Failure defined as a reduction of 50% of asphalt concrete modulus, has been reached in less than a week and more times during the experiments. Failure defined by a limit of permanent deformation of 10-12 mm has been also reached after a few load applications. Also in this case, it has to be underlined how a given model can follow precisely the evolution of measured permanent deformation with the increasing of the number of applications

Analisi C.F.D. dell'iniezione diretta di idrogeno in un motore due tempi

La costante ricerca di nuove tecnologie, da applicare nel campo della generazione di energia e della propulsione, costringe a ricorrere a nuove fonti energetiche migliorando così i rendimenti di conversione e riducendo la produzione di emissioni inquinanti. In tale ottica il lavoro in esame si propone di analizzare l’uso di idrogeno, mediante iniezione diretta, in un motore a due tempi progettato inizialmente per funzionare con alimentazione a benzina. Attraverso un software di modellazione solida sono stati realizzati differenti modelli del motore, caratterizzati da differenti disposizioni degli iniettori sulla testata, che sono stati simulati successivamente mediante un opportuno codice fluidodinamico al fine di indagare la distribuzione dell’idrogeno all’interno del motore durante la fase di compressione

Intergenerational Economic Mobility and Assortative Mating

We use data from the German Socio-Economic Panel and the British Household Panel Survey to estimate the extent of intergenerational economic mobility in a framework that highlights the role played by assortative mating. We find that assortative mating plays an important role. On average about 40-50 percent of the covariancebetween parents' and own permanent family income can be attributed to the person to whom one is married. This effect is driven by strong spouse correlations in human capital.Intergenerational links; Marriage market; Assortative mating; Occupational prestige

Job changes, hours changes and the path of labour supply adjustment

This paper uses the first twelve waves of the British Household Panel Survey covering the period 1991-2002 to investigate single women's labour supply changes in response to three tax and benefit policy reforms that occurred in the 1990s. We find evidence of small labour supply effects for two of such reforms. A third reform in 1999 instead led to a significant increase in single mothers' hours of work. This increase was primarily driven by women who changed job, suggesting that labour supply adjustments within a job are harder than across jobs. The presence of hours inflexibility within jobs and labour supply adjustments through job mobility are strongly confirmed when we look at hours changes by stated labour supply preferences. Finally, we find little overall effect on wages.Job mobility; Hours flexibility; Labour supply preferences; Hours-wage trade-off; Monopsony

Job changes, hours changes and labour market flexibility: panel data evidence for Britain

This study uses the first twelve waves of the British Household Panel Survey covering the period 1991-2002 to investigate the extent of constraints on desired hours of work within jobs and the degree of flexibility of the labour market for a sample of women. Our main findings are as follows. First, the largest movements in hours worked are observed for workers who change their jobs. Second, about 40 percent of the women in the sample are not putting in the hours they would like. Most of them (mainly full-timers) would like to work fewer hours at the prevailing hourly wage. Again, women who change job experience the greatest hours changes, especially if they are over- or under-employed. Third, there is evidence of hours constraints. The hours movements among quitters are up to 5 hours greater than the movements among stayers. Fourth, we do not detect systematic time trends in the relationship between hours changes and job changes. But there is some evidence that overemployed women find it increasingly more difficult to move towards their desired hours even after changing job. Fifth, the evidence on a flexible labour market is mixed. We find only partial support for the hypothesis that overemployed or underemployed quitters receive compensating wage differentials if the new job does not satisfy their hours preferences, as well as for the hypothesis that quitters get a wage premium when they end up moving to jobs that constraint their desired hours.Job mobility; Hours constraints; Labour supply preferences; Hours-wage trade-off; Part-time employment.

On the Origin of the Family

This paper presents an overlapping generations model to explain why humans live in families rather than in other pair groupings. Since most non-human species are not familial, something special must be behind the family. It is shown that the two necessary features that explain the origin of the family are given by uncertain paternity and overlapping cohorts of dependent children. With such two features built into our model, and under the assumption that individuals care only for the propagation of their own genes, our analysis indicates that fidelity families dominate promiscuous pair bonding, in the sense that they can achieve greater survivorship and enhanced genetic fitness. The explanation lies in the free riding behavior that characterizes the interactions between competing fathers in the same promiscuous pair grouping. Kin ties could also be related to the emergence of the family. When we consider a kinship system in which an adult male transfers resources not just to his offspring but also to his younger siblings, we find that kin ties never emerge as an equilibrium outcome in a promiscuous environment. In a fidelity family environment, instead, kinship can occur in equilibrium and, when it does, it is efficiency enhancing in terms of greater survivorship and fitness. The model can also be used to shed light on the issue as to why virtually all major world religions are centered around the importance of the family.fatherhood uncertainty, free riding, kinship systems, religion, overlapping generations, divorce and blended families