This paper revisits Canada's pioneering experience with floating exchange rate over the period 1950-1962. It examines whether the floating rate was the best option for Canada in the 1950s by developing and estimating a New Keynesian small open economy model of the Canadian economy. The model is then used to conduct a counterfactual analysis of the impact of different monetary policies and exchange rate regimes. The main finding indicates that the flexible exchange rate helped reduce the volatility of key macro-economic variables. The Canadian monetary authorities, however, clearly did not understand all of the implications of conducting monetary policy under a flexible exchange rate and a high degree of capital mobility. The paper confirms that monetary policy was more volatile in the post-1957 period and Canada's macroeconomic performance suffered as a result.

In this manuscript I present multiple original works on planets formation theory. Themain goal is to connect the chemical composition of giant planets and small bodies to thephysical and chemical processes taking place in the protoplanetary disk.1. In chapter 1 I introduce the fundamental properties of disks and the basics ofplanets formation theory.2. In chapter 2 I tackle the supersolar C/O and subsolar C/H ratios measured recentlyin WASP 12b. I elaborate a model that tracks water and CO vapors and icesevolution through di_usion, condensation, coagulation, gas drag and sublimation inorder to quantify the variation of the C/O ratio as a function of distance and time.My model shows that, over time, vapors will get permanently depleted inside oftheir respective snowlines with CO getting depleted much slower than water. Thiswill increase the C/O ratio inside of the water snowline from the solar value of 0.55to near unity, allowing the formation of giant planets with C/O _ 1, such as WASP12b. I end this chapter by discussing the observational proofs for the existence ofsuch vapor depletions inside the icelines3. In chapter 3 I use the same model to interpret the chemical composition of Uranusand Neptune. I show how the formation of both planets on the CO snowline's icesoverdensity predicted by this model can explain why both planets are rich in carbon,poor in nitrogen and have subcometary D/H ratios.4. In chapter 4 I shift the discussion to the chemical properties of chondritic meteorites,mainly their D/H ratios. I use a snapshot from a layered (active + dead)zones disk model with a D/H ratio evolution code to check if the non monotonicthermal pro_les in these disks can explain the wide range of D/H ratios measuredin the di_erent chondritic families. I end this chapter by discussing the implicationsof the dead zone disk models for the formation of Jupiter.5. I _nally summarize my results in Conclusions & perspectives, and _nish bypointing out several relevant open questions to be hopefully resolved soon.

This paper assesses the out-of-sample forecasting accuracy of the New Keynesian Model for Canada. We estimate a variant of the model on a series of rolling subsamples, computing out-of-sample forecasts one to eight quarters ahead at each step. We compare these forecasts with those arising from vector autoregression (VAR) models, using econometric tests of forecasting accuracy. We show that the forecasting accuracy of the New Keynesian Model compares favourably with that of the benchmarks, particularly as the forecasting horizon increases. These results suggest that the model could become a useful forecasting tool for Canadian time series. Ce mémoire évalue la précision des prévisions d'un nouveau modèle keynésien pour le Canada à partir d'échantillons. On calibre une variante du modèle sur la base d'une série de sous échantillons récurrents de prévisions de un à huit trimestres d'avance à chaque étape. On compare ces prévisions à celles qui émergent de modèles d'auto régression vectorielle (VAR) en utilisant des tests économétriques de précision de prévision. On montre que la précision des prévisions du nouveau modèle keynésien se compare favorablement à celles des prévisions de référence, particulièrement à proportion que l'horizon temporel s'accroît. Ces résultats suggèrent que le modèle peut devenir un instrument utile de prévision pour les séries chronologiques canadiennes.