<p> The growth rate of the value of farmland is important to the agricultural sector. Real estate  comprises 83% of farm sector assets, as well as 68% of farm sector debt (USDA, 2021). Farm real  estate plays a large role in both sides of the accounting equation and land values – especially  expected future land values – play a significant role in lending decisions. Evaluating these future  land value expectations is the topic of this study. In the US, several organizations use surveys to  elicit farmland experts’ expectations of farmland value. These expectations are presented in the  aggregate, obscuring the potential underlying heterogeneity in the expectation formation process.  Kuethe and Hubbs (2017) found agricultural lenders’ expectations are unbiased yet inefficient, and  recently, Kuethe and Oppedahl (2020) found agricultural lenders’ expectations are conservatively  biased. This study uses an expectation evaluation methodology from Davies and Lahiri (1995) and  a newly-created panel of Indiana farmland experts from the Purdue Land Value and Cash Rent  Survey from 2003-2022 to model heterogeneity in farmland value expectations. We find evidence  of survey-wide under-prediction by farmland experts, consistent with Kuethe and Oppedahl (2020).  In addition, we compare the future price expectations of lenders and appraisers, which may  introduce friction in forming lending relationships. In addition, a key contribution of this study is  the creation of a true panel dataset from past Purdue Land Value and Cash Rent Survey responses.  The novel dataset may allow for future research to explore questions not previously possible, in  absence of a true panel dataset. </p>

I present a simple model of an evolutionary financial market with heterogeneous agents, based on the concept of adaptive belief systems introduced by Brock and Hommes (1997a). Agents choose between different forecast rules based on past performance, resulting in an evolutionary dynamics across predictor choice coupled to the equilibrium dynamics. The model generates endogenous price fluctuations with similar statistical properties as those observed in real return data, such as fat tails and volatility clustering. These similarities are demonstrated for data from the British, German, and Austrian stock market. (author's abstract) / Series: Working Papers SFB "Adaptive Information Systems and Modelling in Economics and Management Science"

The thesis focuses on the analysis of a Behavioral New Keynesian DSGE model. In particular, various specifications of the model are collected from the existing literature and their combinations are simulated. The specifications include heuristics for forecasting output gap, sets of estimated or calibrated parameters and model structures. The resulting simulated output and inflation gap series are compared with the macroeconomic stylized facts and real world data from the US and Euro area based on their distributional characteristics and autocorrelation structures. In addition, a comparison of various simulated model specifications is performed based on the level of correlation between fractions of agents following a specific heuristic and the resulting output and inflation gap values. The distributional characteristics of the US output gap seem to be matched the best by the specifications with unbiased and extrapolative output gap heuristics generating series with higher levels of variance and kurtosis. Contrarily, the Euro output gap is best matched by specifications with optimistic, pessimistic and unbi- ased heuristics producing series with lower levels of variance and kurtosis. Second, the autocorrelation structure of the simulated series tends to mirror the stylized facts as opposed to the...

La presente tesi studia le aspettative in macroeconomia contribuendo alla letteratura esistente sia indagando circa il meccanismo di formazione delle aspettative, sia analizzando come le aspettative a razionalità limitata influenzino la dinamica economica. Nel primo capitolo viene presentato un esperimento nel quale ai soggetti viene chiesto di predire il valore futuro dell'inflazione: a seconda del trattamento, i soggetti possono venire esposti ad un segnale, che mira a stabilizzare l'economia, che fungendo quindi da indicazione prospettica (Forward Guidance). I risultati vengono poi studiati sottolineando il meccanismo di formazione delle aspettative soprattutto in funzione della credibilità del segnale; inoltre viene studiata l'efficacia dello strumento di politica monetaria nella stabilizzazione del sistema economico: si evidenzia come un segnale informativo permetta una sensibile stabilizzazione dell'economia, prevenendo spirali deflazionistiche. Nel secondo capitolo viene sviluppato un modello ad agenti il quale incorpora un meccanismo di formazione delle aspettative a razionalità limitata, derivato da esperimenti precedenti. Inoltre, grazie ad un peculiare processo di aggregazione, viene derivato un modello analiticamente trattabile che permette di studiare il meccanismo di trasmissione di uno shock, isolando gli effetti dovuti all'eterogeneità fra gli agenti e alle aspettative: entrambi gli effetti sono considerevoli ed aiutano nello spiegare la dinamica economica. / The present dissertation analyses expectations in macroeconomics, contributing to the existing literature both studying the expectation formation process, and inquiring how economic dynamic is influenced by boundedly rational expectations. The first chapter presents a learn to forecast experiment in which subject are asked to form expectation regarding the future value of inflation: depending on the treatment, subjects might be exposed to a signal, which possibly aim at stabilizing economy, mimicking the non conventional monetary policy instrument called Delphic Forward Guidance. The collected data are studied trying to recover the underlying expectation formation process highlighting especially the role of credibility of the signal; moreover from the data emerges that informative Forward Guidance helps in stabilizing economy, drastically reducing the probability of deflationary spirals. The second chapter develops an agent-based model, encapsulating a boundedly rational expectation formation process, which had been extrapolated in previous experiments. Moreover benefiting from a specific aggregation procedure, we derive a model characterized by high analytical tractability, allowing hence to study the transmission mechanisms of a shock by insulating the effects due to the heterogeneity among agents and due to expectations: both the effects are sizable and help in understanding the dynamics of the economic system.

In questo lavoro viene analizzata la possibilità che le fluttuazioni economiche possano essere descritte attraverso l'interazione di agenti a razionalità limitata. Accanto a questa ipotesi, si assume anche che gli agenti sono eterogenei. Questi due elementi si inseriscono all'interno del contesto economico che è visto come un sistema complesso in evoluzione popolato da agenti che interagiscono tra loro impiegando differenti strategie decisionali. Questa tesi si sviluppa su tre modelli di riferimento, sviluppati in capitoli separati. Nel primo si studia un mercato immobiliare utilizzando un modello di equilibrio parziale in cui l'ipotesi di aspettative razionali è sostituita da un meccanismo di interazione fra cartisti e fondamentalisti, che è in grado di generare endogenamente lo sviluppo di fasi di boom e bust. Nel secondo viene mostrato come la selezione evolutiva tra diverse strategie di previsione possa spiegare il coordinamento fra comportamenti individuali. Nel terzo si considera un semplice modello macroeconomico costituito da domanda aggregata, offerta aggregata e una regola di politica monetaria per analizzare aspetti quali l'effetto stabilizzante delle diverse politiche monetarie in un sistema popolato da agenti eterogenei. / We investigate the possibility that economic fluctuations can be explained through the interaction of boundedly rational agents, that is, agents are not assumed to be rational. In deviating from rationality and modeling agents as boundedly rational, it is often assumed that agents are heterogeneous. Bounded rationality and learning in a complex environment naturally fit with heterogeneous expectations, with the economy viewed as complex evolving system composed of many different interacting agents, using different decision strategies. This thesis is built around three main economic frameworks, which are developed in separate chapters. In chapter 2 we study the housing market using a partial equilibrium model in which the rational expectations hypothesis is relaxed in favor of chartist-fundamentalist mechanism to allow for the endogenous development of bubbles. In chapter 3 we present evidence that evolutionary selection among different forecasting heterogeneous heuristics can explain coordination on individual behavior. In chapter 4 we consider a simple model made up by the standard aggregate demand function, the New Keynesian Phillips curve and a Taylor rule to deal with different issues, such as the stabilizing effect of different monetary policies in a system populated by heterogeneous agents.

Cette thèse analyse les enjeux du développement économique liés aux dynamiques des cours des matières premières en général et ceux du coton en particulier. Traditionnellement, les travaux s’inscrivant dans une optique de long terme questionnent la pertinence des spécialisations primaires des PMA. À moyen terme l’intérêt porte davantage sur l’instabilité dont les conséquences sont d’autant plus importantes que la dépendance des pays à l’exportation de tels produits est forte. Les enjeux s’articulent alors autour des modalités de régulation des marchés, du choix d'outils (publics ou marchands) pour la gestion des incertitudes, le tout dépendant de l’appréhension de l’instabilité comme un phénomène endogène ou exogène. Dans un contexte nouveau marqué par l’affirmation d’oligopoles de firmes, la segmentation du processus productif mondial, et la financiarisation des marchés de matières premières, nous proposons un cadre analytique permettant d’aborder différemment ces problématiques. Nos travaux montrent d’abord comment les approches du type chaînes globales de valeur peuvent être mobilisées pour mieux orienter les stratégies commerciales / industrielles des PMA. S’appuyant sur la notion de rationalité limitée dans le cadre de modèles de comportements hétérogènes, ils prouvent ensuite l’existence d’une forte composante endogène dans l’instabilité et par là même, l'inefficacité des seuls outils marchands. Au final, pour les pays africains producteurs de coton, il apparait qu’il reste possible de mettre ce produit au service d’une stratégie globale de développement. Cela passe par le recours à des mécanismes hybrides de gestion de l’instabilité, combiné au renforcement des dynamiques de coopération transfrontalières en vue d’une structuration de chaînes régionales de valeur. / This thesis analyzes the economic development issues related to the medium and long-term dynamics of commodities prices in general and cotton prices in particular. Studies on the long-term perspective traditionally question the relevance of primary specializations of LDCs. In the medium term, the interest is relates to price instability for which the consequences are all the more important as countries’ dependency on the exports of such products becomes stronger. The stakes then revolve around market regulation modalities, and the choice of risk management tools (e.g. public or private interventions). These depend on the apprehension of price fluctuations as a phenomenon arising from endogenous or exogenous market factors. In a new economical context influenced by the growing importance of oligopolistic firms, a segmentation of the productive process and the financialization of commodity markets, we address differently these issues through a new analytical framework. The proposed analysis first shows how approaches such as the ones related to global value chains are more adapted to tackle industrial/commercial policies in commodity dependent LDCs. Second, in a context of heterogeneous behavioral models, we rely on the concept of bounded rationality to show the presence of a strong endogenous component in instability. Thus, it proves the inefficiency of private interventions to counter instability. Considering these findings in the case of African cotton producers, we conclude that it remains possible to incorporate the commodity in a global development strategy. But this involves the use of hybrid-type mechanisms (public-private) for managing uncertainty, combined with a reinforcement of cross-border cooperation dynamics in order to structure regional value chains.

Questa tesi esamina l’interazione tra aspettative eterogenee e il rapporto creditore-debitore. In letteratura, non è ancora chiara la natura dell’interazione tra cicli del credito e aspettative individuali. Per questo motivo ho capito che sarebbe stato importante iniziare dai lavori seminali in entrambi i campi, ovvero Kiyotaki & Moore (1997) e Brock & Hommes (1997). Il mio principale obbiettivo è stato quello di studiare più nel dettaglio il funzionamento del vincolo di garanzia. Il fil rouge dell’intera tesi, infatti, è l’analisi del ruolo delle frizioni finanziarie nell’andamento del prezzo di un asset collateralizzato. In particolare, presento un modello dove l’ipotesi di aspettative razionali viene abbandonata. I risultati del primo capitolo rivelano che le aspettative individuali sono una fonte importante di instabilità, anche se la configurazione iniziale risulta stabile. L’elemento che provoca questa instabilità è la bancarotta causata dalla divergenza tra le aspettative di creditori e debitori sul prezzo dell’asset collateralizzato. Poi, nel secondo capitolo, effettuo un esperimento di learning-to-forecast. Fondato sul modello del primo capitolo, ha come obbiettivo quello di testare se e come la volatilità è legata alle percezioni di rischio dei creditori. Ciò che emerge è che ridurre il credito in risposta ad un aumento delle insolvenze in realtà conduce a scenari addirittura peggiori dove il benessere totale si deteriora e il numero delle bancarotte aumenta. / This thesis examines the interaction between heterogeneous expectations and the borrower-lender relationship. In the literature, the nature of the interaction between credit cycle and individual expectations is still unclear. Therefore I realized it was important to start from the seminal works in both fields, that is Kiyotaki & Moore (1997) and Brock & Hommes (1997). My main concern has been to gain insights into the collateral constraint. The common thread of the whole thesis, indeed, is to analyse the role of financial frictions in the price development of a collateralized asset. In particular, I introduce a model where rational expectations are dropped. The results of the first chapter reveal that even in a simple and stable setting, individual beliefs are an important source of instability. The driver of this instability is the bankruptcy caused by the divergence between borrowers' and lenders' price expectations on a collateralized asset. Then, I conduct an online learning-to-forecast experiment. Founded on the model of the first chapter, it tests whether and how volatility is related to lender-level risk perceptions. What emerges is that to shrink credit in response to an increase in defaults actually leads to worse scenarios where total welfare deteriorates and the number of bankruptcies increases.