The main aim of this thesis is to evaluate both short term and long term impact of foreign exchange interventions, which were initiated by Czech central bank in November 2015, on the Czech economy. The first part of the text deals with theoretical aspects of the thesis, especially with the role of central bank and exchange rate, and with the historical development of both the monetary policy in the Czech Republic and Czech crown. Second part of the work investigates the causes that have led to the initiation of intervention régime and tries to clarify whether the triggering was truly justified. The main part of the thesis deals with the launch of interventions itself and also with the short term and longterm impacts on macroeconomic indicators. The end of the work is dedicated to a discussion of intervention regime exit, both to the time aspect and possible scenarios.

日本經濟自1990年起，由「日本第一」落入「流動性陷阱」，而陷入長達10多年的不景氣，主因是日本股市及不動產市場重挫，企業向銀行貸款所提供之擔保品價值下滑，卻因在低利率時代已過度借貸，又經營不善面臨虧損，發生償債困難，一旦財務有所改善，只想提前償還貸款，而無增加貸款意願，故稱為「資產負債表的衰退」（Balance Sheet Recession）。整體經濟景氣蕭條，國內需求不振，亦使振興經濟之寬鬆貨幣政策無法達到預期效果。 日本資產泡沫的破滅使銀行體系的逾放問題日益嚴重。日本政府為了加強銀行體系的健全性，實施金融改革（Big Bang）。使原本以傳統存、放款業務為主的銀行，在面臨國際化浪潮時，也能同時經營證券、保險業務，並將新金融商品引進日本。並由隸屬於內閣府的金融廳(Financial Services Agency)來監督日本銀行及證券業務，負責金融檢查及金融法規企劃業務，落實金融與財政分離之原則。但日本金融業務日益多元化，及衍生性金融商品日趨複雜，對金融監理機關之專業能力，形成新的挑戰。以上所述為日本國內的經濟與金融問題。 至於日圓對外幣的匯率方面，由於日圓利率偏低，套利交易(carry trade) 盛行。投資人趁著日本央行維持低利率之際，借入低成本的日圓資金，然後換成利率較高的外幣轉戰國際市場，追逐收益較高的資產，同時賺取利差、匯率及資產升值的價差，使日圓匯率的走勢疲弱，也造成全球金融市場的波動。 本論文的分析包含： ㄧ、日本經濟不景氣問題剖析：股市及不動產資產泡沫化 二、日本金融危機形成原因：資產價格下跌，影響抵押品價值，企業償債能力變差，故使銀行不良債權增加。 三、日本總體經濟近況（GDP、CPI、失業率的變化）及經濟復甦後日本央行貨幣政策的改變 四、日本金融市場如股市、房地產市場及日本政府債券（JGB）市場的分析及展望。 五、探討日本銀行業獲利能力、不良債權問題、資本適足率以及銀行業股價指數的變化。 六、根據台灣以及日本最近的發展對金融監理單位及銀行業提出應有的改革與建議。 / The Japanese economy fell into a “liquidity trap” in 1990. Due to the stock market and real estate market plunge, the deep recession has lasted for over 10 years. The bursting of asset bubbles caused the balance sheets of enterprises to become weaker and weaker. All companies hoped to reduce their debt to banks if they were profitable. They had no intention to reinvest any more. So it was called - Balance Sheet Recession. Even though the Bank of Japan adopted an easy monetary policy, the financial system remained vulnerable. With the bad debt of commercial banks increasing, the NPL (non-performing loan) problem has been a major concern for city banks and regional banks. Japan's "Big Bang" reforms radically altered its financial marketplace. The barriers separating banks, securities, and insurance companies were lowered. The Financial Services Agency replaced Ministry of Finance to oversee banking, securities and exchange and insurance in order to ensure the stability of the financial system. As for financial business diversified and derivative products complicated, there were many great challenges facing the financial regulatory authorities. During the past decade, the yen carry trade has become a target for many investors or speculators. Traders using this strategy attempt to capture the difference between the interest rates of two currencies. Taking USD/Yen for example, they borrowed the cheaper yen and invested in U.S. Treasuries yielding a higher interest rate. It causes the depreciation of Japanese Yen and increases the volatility of financial markets. This essay describes Japanese financial crisis, Japanese monetary policy, stock market, and real estate market. Besides, I analyze the profitability, capital adequacy, and non-performing problems of Japanese banks. Finally, I give my personal opinions on Taiwan and Japan’s banking industry.

The thesis studies three distinct issues in monetary economics using a common dynamic general equilibrium approach under the assumptions of rational expectations and nominal price rigidity. The first chapter deals with the so-called "liquidity trap" - an issue which was raised originally by Keynes in the aftermath of the Great Depression. Since the nominal interest rate cannot fall below zero, this limits the scope for expansionary monetary policy when the interest rate is near its lower bound. The chapter studies the conduct of monetary policy in such an environment in isolation from other possible stabilization tools (such as fiscal or exchange rate policy). In particular, a standard New Keynesian model economy with Calvo staggered price setting is simulated under various alternative monetary policy regimes, including optimal policy. The challenge lies in solving the (otherwise linear) stochastic sticky price model with an explicit occasionally binding non-negativity constraint on the nominal interest rate. This is achieved by parametrizing expectations and applying a global solution method known as "collocation". The results indicate that the dynamics and sometimes the unconditional means of the nominal rate, inflation and the output gap are strongly affected by uncertainty in the presence of the zero lower bound. Commitment to the optimal rule reduces unconditional welfare losses to around one-tenth of those achievable under discretionary policy, while constant price level targeting delivers losses which are only 60% larger than under the optimal rule. On the other hand, conditional on a strong deflationary shock, simple instrument rules perform substantially worse than the optimal policy even if the unconditional welfare loss from following such rules is not much affected by the zero lower bound per se. The second thesis chapter (co-authored with Andrea Pescatori) studies the implications of imperfect competition in the oil market, and in particular the existence of a welfare-relevant trade-off between inflation and output gap volatility. In the standard New Keynesian model exogenous oil shocks do not generate any such tradeoff: under a strict inflation targeting policy, the output decline is exactly equal to the efficient output contraction in response to the shock. I propose an extension of the standard model in which the existence of a dominant oil supplier (such as OPEC) leads to inefficient fluctuations in the oil price markup, reflecting a dynamic distortion of the economy's production process. As a result, in the face of oil sector shocks, stabilizing inflation does not automatically stabilize the distance of output from first-best, and monetary policymakers face a tradeoff between the two goals. The model is also a step away from discussing the effects of exogenous oil price changes and towards analyzing the implications of the underlying shocks that cause the oil price to change in the first place. This is an advantage over the existing literature, which treats the macroeconomic effects and policy implications of oil price movements as if they were independent of the underlying source of disturbance. In contrast, the analysis in this chapter shows that conditional on the source of the shock, a central bank confronted with the same oil price change may find it desirable to either raise or lower the interest rate in order to improve welfare. The third thesis chapter (co-authored with Andrea Pescatori) studies the extent to which the rise in US macroeconomic stability since the mid-1980s can be accounted for by changes in oil shocks and the oil share in GDP. This is done by estimating with Bayesian methods the model developed in the second chapter over two samples - before and after 1984 - and conducting counterfactual simulations. In doing so we nest two other popular explanations for the so-called "Great Moderation": (1) smaller (non-oil) shocks; and (2) better monetary policy. We find that the reduced oil share can account for around one third of the inflation moderation, and about 13% of the GDP growth moderation. At the same time smaller oil shocks can explain approximately 7% of GDP growth moderation and 11% of the inflation moderation. Thus, the oil share and oil shocks have played a non-trivial role in the moderation, especially of inflation, even if the bulk of the volatility reduction of output growth and inflation is attributed to smaller non-oil shocks and better monetary policy, respectively. / La tesis estudia tres problemas distintos de macroeconomía monetaria utilizando como marco común el equilibrio general dinámico bajo expectativas racionales y con rigidez nominal de los precios. El primer capítulo trata el problema de la "trampa de liquidez" - un tema planteado primero por Keynes después de la Gran Depresión de 1929. El hecho de que el tipo de interés nominal no pueda ser negativo limita la posibilidad de llevar una política monetaria expansiva cuando el tipo de interés se acerca a cero. El capítulo estudia la conducta de la política monetaria en este entorno en aislamiento de otros posibles instrumentos de estabilización (como la política fiscal o la política de tipo de cambio). En concreto, se simula un modelo estándar Neo-Keynesiano con rigidez de precios a la Calvo bajo diferentes regimenes de política monetaria, incluida la política monetaria óptima. El reto consiste en resolver el modelo estocástico bajo la restricción explícita ocasionalmente vinculante de no negatividad de los tipos de interés. La solución supone parametrizar las expectativas y utilizar el método de solución global conocido como "colocación". Los resultados indican que la dinámica y en ocasiones los valores medios del tipo de interés, la inflación y el output gap están muy influidos por la presencia de la restricción de no negatividad. El compromiso con la regla monetaria óptima reduce las pérdidas de bienestar esperadas hasta una décima parte de las pérdidas obtenidas bajo la mejor política discrecional, mientras una política de meta constante del nivel de precios resulta en pérdidas que son sólo 60% mayores de las obtenidas bajo la regla óptima. Por otro lado, condicionado a a un choque fuerte deflacionario, las reglas instrumentarias simples funcionan mucho peor que la política óptima, aun si las pérdidas no condicionales de bienestar asociadas a dichas reglas no están muy afectadas por la presencia de la restricción de no negatividad en si. El segundo capítulo de la tesis estudia las implicaciones de la competencia imperfecta en el mercado del petróleo, y en concreto la existencia de un conflicto relevante entre la volatilidad de la inflación y la del output gap de un país importador de petróleo. En el modelo estándar Neo Keynesiano, los choques petroleros exógenos no generan ningún conflicto de objetivos: bajo una política de metas de inflación estricta, la caída del output es exactamente igual a la contracción eficiente del output en respuesta al choque. Este capitulo propone una extensión del modelo básico en la cual la presencia de un proveedor de petróleo dominante (OPEP) lleva a fluctuaciones ineficientes en el margen del precio del petróleo que reflejan una distorsión dinámica en el proceso de producción de la economía. Como consecuencia, ante choques provinientes del sector de petróleo, una política de estabilidad de los precios no conlleva automáticamente a una estabilización de la distancia del output de su nivel eficiente y existe un conflicto entre los dos objetivos. El modelo se aleja de la discución los efectos de cambios exógenos en el precio del petróleo y se acerca al análisis de las implicaciones de los factores fundamentales que provocan los cambios en el precio del petróleo en primer lugar. Esto último representa una ventaja clara frente a la literatura existente, la cual trata tanto los efectos macroeconómicos como las implicaciones para la política monetaria de cambios en el precio del petróleo como si éstos fueran independientes de los factores fundamentales provocando dicho cambio. A diferencia de esta literatura, el análisis del capitulo II demuestra cómo frente al mismo cambio en el precio del petróleo, un banco central puede encontrar deseable bien subir o bajar el tipo de interés en función del origen del choque. El tercer capitulo estudia el grado en que el ascenso de la estabilidad macroeconómica en EE.UU. a partir de mediados de los 80 se puede atribuir a cambios en la naturaleza de los choques petroleros y/o el peso del petróleo en el PIB. Con este propósito se estima el modelo desarrollado en el capitulo II con métodos Bayesianos utilizando datos macroeconómicos de dos periodos - antes y después de 1984 - y se conducen simulaciones contrafactuales. Las simulaciones permiten dos explicaciones alternativas de la "Gran Moderación": (1) menores choques no petroleros; y (2) mejor política monetaria. Los resultados apuntan a que el petróleo ha jugado un papel no-trivial en la moderación. En particular, el menor peso del petroleo en el PIB a partir de 1984 ha contribuido a una tercera parte de la moderación de la inflación y un 13% de la moderación del output. Al mismo tiempo, un 7% de la moderación del PIB y 11% de la moderación de la inflación se pueden atribuir a menores choques petroleros.

Dans cette thèse, je fournis une évaluation empirique des relations entre les principales variables macroéconomiques qui animent le cycle économique. Nous traitons dans chacun des trois chapitres une question empirique en utilisant une approche économétrique bayésienne. Dans le premier chapitre nous étudions la contribution conditionnelle des taux de transition du marché du travail (le taux de retour en emploi et le taux de séparation). La littérature n'est pas parvenue à un consensus sur lequel des taux dominent la dynamique du marché du travail. Alors que Blanchard et Diamond (1990) ont conclu que la baisse de l'emploi en période de récession résulte d'un taux de séparation plus élevé, Shimer (2012), ainsi que Hall (2005), expliquent que les variations du chômage sont principalement expliqués par la variation du taux de retour en emploi. Notre résultat, obtenu grâce à une estimation d'un modèle VAR structurel, montre que l'importance de chaque taux de transition dépend des chocs qui ont frappé le marché du travail et de l'importance des institutions du marché du travail. Dans le second chapitre, nous évaluons l'impact de la réforme du marché du travail réalisée par le Président des États-Unis H. Hoover au début de la Grande Dépression. Nous montrons que ces politiques ont permis à l'économie américaine d'échapper à une grande spirale déflationniste. L'estimation d'un modèle DSGE à l'échelle agrégée, nous permet de comparer deux effets opposés que ces politiques impliquent : effet négatif dû à une baisse de l'emploi et l'effet positif dû aux anticipations inflationnistes qui sont expansionnistes quand l'économie est dans la trappe à liquidité. Les résultats dépendent de la règle de politique monétaire que nous supposons : le principe de Taylor ou le ciblage du niveau de prix. Le troisième chapitre est consacré à la relation entre le taux d'intérêt réel et l'activité économique qui dépend du nombre des participants aux marchés financiers. En utilisant un modèle DSGE et en permettant à la proportion de ces agents d'être stochastiques en suivant une chaîne de Markov, nous identifions les périodes historiques où la proportion était assez faible pour inverser la courbe IS. Pour le cas des États-Unis, nous montrons que cette relation est positive pendant la période de la Grande Inflation et pendant une courte période au début de la Grande Récession. Dans l'union européenne, la proportion de non­-participants a été augmentée pendant les années 2009-2015 mais seulement pour amplifier la corrélation négative entre le taux d'intérêt réel et la croissance de la production. / In this thesis I provide an empirical assessment of the relations between the main macroeconomic variables that drive the Business Cycle. We treat the empirical question that arises in each chapter using Bayesian estimation. In the first chapter we investigate conditional contribution of the labor market transition rates (the job finding rate and the separation rate) to unemployment. The literature did not have a consensus on which rate dominates in explaining the labor market dynamics. While Blanchard and Diamond (1990) concluded that the fall in employment during slumps resulted from a higher separation rate, Shimer (2012), as well as Hall (2005), explain unemployment variations by mainly the job finding rate. Our result, obtained through an estimation of a structural VAR model, shows that the importance of the transition rated depends on the shocks that hit an economy and hence the importance of the labor market institutions. In the second chapter, we assess the impact of the labor market reform of the US president H. Hoover implemented at the beginning of the Great Depression. We show that these policies prevented the US economy to enter a big deflationary spiral. Estimating a medium scale DSGE model, we also compare two opposite effects these policies lead to: negative effect through a fall in employment and positive effect though inflationary expectations which are expansionary when monetary policy is irresponsive to the rise in prices. The results depend on the monetary policy rule we assume: The Taylor principle or price level targeting. The third chapter is devoted to the relation between the real interest rate and the economic activity which depends on the number of asset market participants. Using a DSGE model and allowing to the proportion of these agents to be stochastic and to follow a Markov chain, we identify the historical sub-periods where this proportion was low enough to reverse the IS curve. For the US case, we report the studied relation to be positive during the Great Inflation period and for a short period at the edge of the Great Recession. In the EA, the proportion of non-participants has been increased during 2009-2015, but only to amplify the negative correlation between the real interest rate and output growth.

This thesis examines the measurement, applications and properties of consumer inflation expectations in the context of eight European Union countries: France, Germany, the UK, Spain, Italy, Belgium, the Netherlands and Sweden. The data proceed mainly from the European Commission's Consumer Survey and are qualitative in nature, therefore requiring quantification prior to use. This study first seeks to determine the optimal quantification methodology among a set of approaches spanning three traditions, associated with Carlson-Parkin (1975), Pesaran (1984) and Seitz (1988). The success of a quantification methodology is assessed on the basis of its ability to match quantitative expectations data and on its behaviour in an important economic application, namely the modelling of wages for our sample countries. The wage equation developed here draws on the theoretical background of the staggered contracts and the wage bargaining literature, and controls carefully for inflation expectations and institutional variables. The Carlson-Parkin variation proposed in Curto Millet (2004) was found to be the most satisfactory. This being established, the wage equations are used to test the hypothesis that the advent of EMU generated an increase in labour market flexibility, which would be reflected in structural breaks. The hypothesis is essentially rejected. Finally, the properties of inflation expectations and perceptions themselves are examined, especially in the context of EMU. Both the rational expectations and rational perceptions hypotheses are rejected. Popular expectations mechanisms, such as the "rule-of-thumb" model or Akerlof et al.'s (2000) "near-rationality hypothesis" are similarly unsupported. On the other hand, evidence is found for the transmission of expert forecasts to consumer expectations in the case of the UK, as in Carroll's (2003) model. The distribution of consumer expectations and perceptions is also considered, showing a tendency for gradual (as in Mankiw and Reis, 2002) but non-rational adjustment. Expectations formation is further shown to have important qualitative features.

The aim of this thesis is to enhance our understanding of Swedish marine insurers' choices of business strategies under the potentially difficult business circumstances of the interwar period 1918-1939. Little previous research exists on marine insurance during the interwar period. This is remarkable in the Swedish context since the Swedish economy has traditionally depended on its exports. The focus on Sweden is justified since the Swedish insurance market saw regulatory stability during the interwar period. It was also characterised by the coexistence of stock and mutual insurers, allowing this thesis to contribute with insights on potentially problematic insurance cartelisaton. This thesis employs a mixed methods design, including qualitative methods and regression analysis. To interpret results, this thesis employs insurance risk theory, cartel theory, theories on reinsurance and risk diversification, and agency theory. By employing this combination of theories, it is possible to explain choices and outcomes of adopted strategies both with reference to particularities of marine insurance and with reference to particularities of the two different organisational forms. The results show that the insurers conceived several new characteristics of their business environment as challenges and implemented both cartel strategies and company-specific strategies of risk diversification. Among the challenges were rapid inflation, rapidly decreasing prices and business volumes in shipping and trade, the introduction of motor ships, and the existence of naval mines on many trade routes. Also, exchange-rate fluctuations were considered to cause losses on established marine insurance contracts and rendered business results uncertain. Swedish insurers adopted cartel strategies from 1918 through The Swedish Association of Marine Underwriters (Sjöassuradörernas Förening) since they had anticipated a post-war crisis. Market division agreements were adopted for the most attractive market segments, but eventually price agreements became the primary cartel strategy, supported by prohibitions of competition. The work on price agreements sometimes increased the market efficiency since it reduced uncertainty, for instance in insurance of cargo with motor ships. Few price agreements were however adopted for the insurance of shipping since that market segment was dominated by mutual insurers, highlighting the difficulties of cartelisation in insurance markets inhabited by both stock and mutual insurers. The cartel further adopted reinsurance agreements to create barriers to entry in the Swedish marine insurance market. It however experienced prominent difficulties to implement the cartel strategies. One prominent difficulty of implementation was cheating. Also international competition created difficulties. The cartel companies therefore engaged in international cartelisation through The International Union of Marine Insurance (Internationaler Tranport-Versicherungs-Verband) from the late 1920s. This international cartel sought to reduce international competition by agreements not to compete in foreign markets. It also sought to manage the exchange-rate fluctuations of the early 1920s and the early 1930s by agreements among marine insurers, but it failed to obtain sufficient support. In spite of cartelisation, the returns on marine insurance were pushed down by the recognized challenges during the early 1920s, inflicting losses. The business however recovered and remained profitable throughout the 1930s, showing that the great depression was not as great as the deflation crisis in marine insurance. Exchange-rate fluctuations affected the international competitive strength of both stock and mutual insurers and additionally influenced the stock insurers' returns on established marine insurance contracts. The insurers were however compensated for the poor marine business results of the early 1920s by greater reliance than previously on reinsurers and by diversification among insurance lines, which rendered profits less negative than the returns on marine insurance. The business ceded to reinsurers on average inflicted losses during each of the first seven years of the 1920s. These losses were indirectly caused by World War I since that war had caused the establishment of new reinsurers in different countries, not the least in Scandinavia, and in turn caused over capacity during the 1920s. New contractual formulations evolved internationally to the benefit of ceding insurers, indicating information asymmetries. Exits became frequent among reinsurers. In effect, into the 1930s, ceding insurers internationally found it difficult to obtain obligatory reinsurance treaties. During the early 1920s, the Swedish stock marine insurers also increasingly diversified their insurance businesses among insurance lines. This process had been catalysed by World War I, was accelerated during the 1920s, and continued into the 1930s. / Syftet med denna avhandling är att förståeliggöra svenska marinförsäkringsbolags val av affärsstrategier under mellankrigstiden 1918-1939, en period som kännetecknades av potentiellt svåra affärsförhållanden. Försäkringsverksamhet är känslig för ekonomiska kriser, men har uppmärksammats mindre än bankverksamhet när det gäller mellankrigstiden. Inte minst marinförsäkring är känslig för ekonomiska kriser eftersom de försäkrade verksamheterna, sjöfart och handel, endast förekommer i den mån som transporterade varor efterfrågas. Tidigare forskning har endast i liten omfattning fokuserat på marinförsäkring, vilket ur ett svenskt perspektiv kan tyckas anmärkningsvärt med tanke på att den svenska ekonomin har i hög grad varit beroende av sjöburen handel. En studie av svensk marinförsäkring är motiverad ur ett internationellt perspektiv eftersom den svenska försäkringslagstiftningen förblev i stort sett oförändrad under perioden, vilket gör det rimligt att tolka marinförsäkringsbolags val av affärsstrategier som svar på ekonomiska omständigheter. Under mellankrigstiden var katellstrategier ett vanligt svar på svåra affärsförhållanden i olika verksamheter, men kartellisering var potentiellt problematisk i marinförsäkring eftersom den verksamheten är internationell och eftersom marinförsäkring är en heterogen produkt. Dessutom befolkades den svenska försäkringsmarknaden av både aktiebolag och ömsesidiga bolag, vilket är ett ytterligare potentiellt hinder för kartellisering. Studier av kartellisering under potentiallt svåra förutsättningar kan bidra med insikter om under vilka förutsättningar karteller uppstår, vilket ytterligare motiverar studien. Denna avhandling analyserar även två företagsspecifika riskdiversifieringsstrategier, som potentiellt kan kompensera för låg avkastning på mottagen försäkring, nämligen återförsäkring och diversifiering mellan försäkringsgrenar. Återförsäkring har av tidigare forskning framhållits som ett underutforskat område. Avhandlingen tillämpar både kvalitativa och kvantitativa undersökningsmetoder. För att uttolka de empiriska resultaten tillämpas riskteori för försäkring, kartellteori, återförsäkringsteori, riskdiversifieringsteori, samt incitamentsteori på företagsnivå (agency theory). Denna kombination av teorier gör det möjligt att förklara strategival med utgångspunkt både i marinförsäkringens karaktäristika och i de båda olika organisationsformers karaktäristika. Resultaten visar att försäkringsbolagen noterade ett antal nya affärsförhållanden som utmaningar och att dessa bolag implementerade både kartellstrategier och företagsspecifika riskdiversifieringsstrategier. Bland de noterade utmaningarna märks snabb inflation, snabbt fallande priser och affärsvolymer i sjöfart och handel, införandet av motorfartyg, samt sjöminor på många fartygsrutter. Försäkringsbolagen behärskade endast lite erfarenhet av risker associerade med motorfartyg och sjöminor, vilket gjorde riskbedömningar osäkra. Även växelkursfluktuationer uppfattades som utmaningar eftersom de orsakade förluster på etablerade marinförsäkringskontrakt och skapade problem att förutsäga affärsresultaten. Från 1918 antog svenska marinförsäkringsbolag kartellstrategier genom branschorganisationen Sjöassuradörernas Förening, detta eftersom de förväntade sig en efterkrigskris. Marknadsuppdelningsavtal infördes i attraktiva marknadssegment, men med tiden blev prisöverenskommelser den främsta kartellstrategin, understödd av avtal som förbjöd konkurrens. Arbetet med prisöverenskommelser ökade marknadseffektiviteten i vissa marknadssegment, detta genom att reducera osäkerheten i riskbedömningarna. Ett tydligt exempel på ett sådant marknadssegment är försäkring av varor transporterade med motorfartyg. Kartellen etablerade däremot få prisöverenskommelser för försäkring av sjöfart eftersom detta marknadssegment dominerades av ömsesidiga försäkringsbolag. Denna kontrast mellan varuförsäkring och sjöfartsförsäkring belyser svårigheterna med att kartellisera en försäkringsmarknad som befolkas både av aktiebolag och av ömsesidiga bolag. Kartellen antog också återförsäkringsavtal i syfte att skapa etableringshinder på den svenska försäkringsmarknaden. Den upplevde emellertid svårigheter att implementera överenskommelserna, såsom brott mot prisöverenskommelserna och mot konkurrensförbuden. Ytterligare svårigheter skapades av internationell konkurrens. Från slutet av 1920-talet deltog därför kartellbolagen i den internationella marinförsäkringskartellen Internationaler Tranport-Versicherungs-Verband (senare benämnd The International Union of Marine Insurance). Medlemsbolagen i denna internationella kartell skapade överenskommelser med innebörden att utländska försäkringstagare inte skulle erbjudas försäkring. Dessa överenskommelser syftade till att reducera den internationella konkurrensen. Denna kartell försökte också reducera effekterna för marinförsäkringsbolag av växelkursfluktuationer genom överenskommelser om hur växelkurser skulle beräknas i marinförsäkringsfrågor. Sådana försök gjordes både under de första åren av 1920-talet och under de första åren av 1930-talet. Det avsedda resultatet kunde emellertid inte nås, detta eftersom uppslutningen förblev otillräcklig. Trots kartelliseringen reducerades avkastningen på marinförsäkring till förlustnivåer under det tidiga 1920-talet. Avkastningen förbättrades sedan stegvis och förblev positiv under 1930-talet. I marinförsäkring var alltså den stora depression inte lika stor som deflationskrisen. Växelkursfluktuationer påverkade både aktiebolags och ömsesidiga bolags internationella konkurrenskraft. Dessutom påverkade växelkurserna aktiebolagens avkastning på etablerade marinförsäkringskontrakt. Försäkringsbolagen kompenserades för 1920-talets förlustresultat i marinförsäkring genom ökad cedering av risk till återförsäkringsbolag och genom diversifiering av de mottagna riskerna mellan olika försäkringsgrenar. Under 1920-talet var bolagens vinster därför mindre negativa än resultaten i marinförsäkring. Den affär som cederades till återförsäkringsbolag var i genomsnitt förlustbringande under vart och ett av 1920-talets första sju år. Dessa förluster orsakades indirekt av första världskriget, eftersom det kriget stimulerade etablering av nya återförsäkringsbolag, detta i olika länder och inte minst i Skandinavien. I förlängningen skapade första världskriget därmed överkapacitet på återförsäkringsmarknaden. Nya kontraktsformuleringar introducerades internationellt till de cederande bolagens fördel. Detta förhållande indikerar informationsasymmetrier i relationen mellan cederande och mottagande försäkringsbolag. Många återförsäkringsbolag lämnade marknaden. Resultatet blev att cederande bolag under början av 1930-talet i olika länder fick svårigheter att sluta obligatoriska återförsäkringsavtal. Under början av 1920-talet diversifierade aktiebolagen också sin verksamhet mellan olika försäkringsgrenar. Denna process katalyserades av första världskriget, accelererade under början av 1920-talet och fortsatte in på 1930-talet.