boom and bust cycles external imbalances and the real exchange rate when the current account balance and net capital outflows do not exactly offset each other international payment flows arise payment flows into a country push the real exchange rate up payment outflows push it down this article uses a model of optimal consumption and portfolio choice to determine the factors that drive international payment flows during boom and bust cycles it shows that during such episodes capital inflows first exceed the deficit on current account strengthening the currency later on when the return on domestic capital reverts to its normal level the current account recovers yet the overall decline of the net foreign asset position provokes a fall of the real exchange rate even below its initial level case studies of countries experiencing rapid economic expansions followed by economic and financial meltdowns confirm the article s theoretical predictions

the speculative attack on the peso and the real exchange rate argentina 1979 1981 abstract this article applies a speculative attack model to argentina during its pre announced exchange rate system from january 1 1979 to june 30 1981 the model attempts to verify a rule whereby if domestic credit growth exceeds the rate of currency depreciation two things occur first the domestic price of non traded goods rises relative to the price of traded goods second foreign reserves decline until a point when a sudden speculative attack depletes remaining reserves causes a precipitous fall in the relative price of non tradables and forces the country onto a floating exchange rate regime in some important respects the model captures the argentinian experience yet in other respects if fails to do so

crises and exchange rate regimes time to break down the bipolar view we revisit the link between crises and exchange rate regimes err using a panel of 90 developed and developing countries over the period 1980 2009 we find that corner err are not more prone to crises compared to intermediate err this finding holds for different types of crises banking currency and debt and is robust to a wide set of alternative specifications consequently we clearly break down the traditional bipolar view countries that aim at preventing crisis episodes should focus less on the choice of the err and instead implement sound structural macroeconomic policies

collusion and overlending i introduction for a long time have korean companies been engaged in unbridled expansionism financed through loans inefficient octopus style management and over and duplicate investment thus expediting the structural failure of the economy this failure to concentrate on profits consolidation and efficiency provided the fuse to the bankruptcy bombs that triggered the foreign exchange and economic crises the collusion between the conglomerates financial sector and politicians made this financial monopoly possible chosun ilbo december 26 1997 collusion and overlending in the korean financial sector may be best illustrated by the above editorial highlight of chosun ilbo the most read newspaper in korea its 1997 financial crisis is primarily triggered by continual bankruptcies of chaebols conglomerates which with assistance from politicians had borrowed heavily from financial institutions in financing their investment projects 1 unlike some other asian countries experiencing problems in their financial sector due to shifts in investment projects toward real estates such as japan hong kong and thailand chaebols in korea concentrated mostly on manufacturing activities 2 in this study we establish a tractable model of overlending with three key players namely chaebols financial institutions and politicians as highlighted in chosun ilbo the model is designed to achieve two primary goals that are crucial for matching some key observations during the korean turmoil first we illustrate how overlending can be an equilibrium outcome with collusion between chaebols and politicians when the economic environment is favorable this occurs despite that such a collusion distorts normal borrowing lending operation by causing a discernible shift in loan composition from more to less productive investment projects second we show that as the economic environment gradually deteriorates there can be a shift from a collusion to a no collusion equilibrium the combination of deterioration in fundamentals and expectations of an equilibrium shift can trigger economy wide financial crisis more specifically we construct a simple principal supervisor agent model of corruption and overlending the principal is the formal authority of loan decision making of a financial institution or in short the financial institution the supervisor is a politician who serves as the informational intermediary in the borrowing lending arrangement via his her connections and networking 3 the agent is a chaebol of an unknown type which seeks for external financing of a set of risky projects a politician s favorable signal about the borrowing chaebol s overall performance would grant the approval of the loan to finance an array of risky projects whose returns depend on idiosyncratic shocks that cannot be washed out in aggregation within the chaebol as an outside alternative to making the loan the financial institution can invest in the world capital market where a fixed rate of return is guaranteed this portfolio decision depends on a comparison of the expected average returns on the given set of risky projects with the safe returns on investments in the world capital market while both the chaebol s type and the state of nature are unobservable to the financial institution we for simplicity assume that politician s connections and networking can fully uncover the true type of the chaebol this valuable information possessed by the politician is one that the financial institution has an incentive to purchase but a low type chaebol has an incentive to conceal whether the politician ends up revealing truthfully this information depends on how much to obtain from the lender in terms of general support versus how much to gain from the borrower in terms of bribes or side payments when a low type chaebol has the politician on its side information is distorted and a collusion equilibrium arises

macroeconomic policy in a two party system as a repeated game this paper considers the interaction of two parties with different objectives concerning inflation and unemployment and rational and forward looking wage setters if discretionary policies are followed an economic cycle related to the political cycle results in equilibrium this cycle is significantly different from the traditional political business cycle reputational mechanisms due to the repeated interaction of the two parties and the public or commitments to a common policy rule can improve upon the discretionary outcome by reducing or eliminating the magnitude of the economic fluctuations

optimal anti inflation programs in semi industrialized economies orthodox versus heterodox policies abstract the paper characterizes the optimal time consistent anti inflation program in a small open semi industrialized economy when policy makers choose the rate of exchange rate crawl the rate of change of fiscal spending and a wage and price control parameter to minimize deviations of output and inflation the optimal program involves a rapidly decelerating rate of crawl a sharp reduction in spending and a short initial period of wage and price controls the paper also assesses the importance of controls in helping to reduce the output loss associated with fighting inflation

the politics of speculative attacks in industrial democracies recent models of speculative currency crises contend that market expectations of policy behavior can trigger a speculative attack we argue that political processes and partisan objectives inform expectations about the government s commitment to the exchange rate first market actors anticipate periods when the partisan identity of a government may change through an election or a cabinet collapse second party labels provide information to currency traders about the policy objectives of a potential government consequently we contend that the probability of a speculative attack will be higher when markets expect the cabinet to end and when the cabinet dissolution is likely to produce a leftward shift in policy a discrete timesurvival model is used to estimate the probability that a cabinet will dissolve in any given month for sixteen parliamentary democracies from 1970 to 1995 the predicted values are then used as a proxy for market expectations in a model of speculative currency crises

seigniorage revenue deficits and self fulfilling currency crises abstract this paper examines potential resolutions to the conflict between a fixed exchange rate and seigniorage revenue requirement of a stylized developing economy that gives rise to a currency crisis the government has an informational advantage and can decide when it is optimal to invoke an escape clause i e to drop the peg and float speculators must guess when the crisis will happen based on their assessment of the probability of collapse and this makes pegged exchange rate equilibria unstable

presidential and congressional vote share equations three vote share equations are estimated and analyzed in this paper one for presidential elections one for on term house elections and one for mid term house elections the sample period is 1916 2006 considering the three equations together allows one to test whether the same economic variables affect each and to examine various serial correlation and coattail possibilities the resulting three equation model can then be analyzed dynamically which is done in section 4 the main conclusions are briefly 1 there is strong evidence that the economy affects all three vote shares and in remarkably similar ways 2 there is no evidence of any presidential coattail effects on the on term house elections the presidential vote share and the on term house vote share are highly positively correlated but this is because they are affected by some of the same variables 3 there is positive serial correlation in the house vote in that the previous mid term house vote share positively affects the on term house vote share and the previous on term house vote share positively affects the mid term house vote share 4 the presidential vote share has a negative effect on the next mid term house vote share the most likely explanation for this is a balance argument where voters are reluctant to let one party become too dominant ruled out as possible explanations for this fourth result is any reversal of a coattail effect since there is no evidence of an effect in the first place and a regression to the mean since the positive serial correlation in the house vote implies no such regression also it is not simply voting against the party in the white house because the presidential variable is a vote share variable not a 0 1 incumbency variable

how they lost the presidency abstractfor the second time in this century and the fifth time in us history the 2016 presidential popular vote winner was not elected president one day before the election the author predicted

speculative currency attacks and balance of payments crises abstract this paper reviews the recent theoretical literature on collapsing exchange rate regimes using a combination of technique intuition and realworld observation we discuss the literature s main insights point out some unresolved questions and offer suggestions for future research the survey should be of interest to both specialists and non specialists in the field of international macroeconomics

credibility and policy convergence in a two party system with rational voters the traditional approach to modeling political parties behavior based upon the contribution of anthony downs 1957 assumes that the parties unique objective is to win elections thus they maximize their popularity the crucial implication of this assumption for a two party system is that if the two parties have the same information about voters preferences full convergence of policies results from electoral competition this is the crucial implication of the median voter theorem more generally it may be argued that different parties are motivated differently because they represent different constituencies parties may not care only about winning elections per se but also about the quality of the policies resulting from an election in this case the candidates of the two parties view winning an election not only as a goal per se but also as a means of implementing a better policy for their respective constituencies this paper shows that electoral competitions imply dynamic inconsistency if the voters are modeled as rational and forwardlooking agents and parties do not care exclusively about being elected but also about which policy to implement once elected the dynamic inconsistency arises as follows the parties have an incentive to announce convergent platforms to increase their chances of election however if the elected party is not committed to its electoral platform it has an incentive to follow its most preferred policy rather than the policy announced in its platform if voters are rational they account for this incentive thus in general in a one shot electoral game the only timeconsistent equilibrium is one in which no convergence is possible the two parties follow their most preferred policies and the voters rationally expect this outcome full convergence of parties platforms results only as a limiting case when the parties are completely indifferent with respect to the quality of the policies resulting from the election thus these results differ from the existing literature on ideologically motivated politicians for instance donald wittman 1977 1983 randall calvert 1985 which implicitly assumes the possibility of binding commitments to electoral platforms complete or partial policy convergence can be the outcome of political competition if the interaction between the parties and the voters is modeled as an infinitely repeated game in fact if the candidates have concave objective functions the welfare maximizing policy rule implies a complete convergence of parties policies however this cooperative and agreed upon policy may or may not be sustainable as a subgame perfect equilibrium depending on parameter values in particular it depends on the discount rates of the two parties the degree of polarization of their preferences and the relative popu graduate school of industrial administration carnegie mellon university pittsburgh pa 15213 and national bureau of economic research cambridge ma 02138 this paper is based upon a chapter of my unpublished doctoral dissertation at harvard university i am greatly indebted to jeffrey sachs for directing my attention toward these issues and for many conversations i also wish to thank andrew abel dilip abreu olivier blanchard ramon caminal andrew caplin alex cukierman morris fiorina benjamin friedman herschel grossman howard rosenthal and the referees for very useful comments the responsibilitv af anv n mtnkieis af calrirp nfnlv mine the result of policy convergence in a two party system is more general than the median voter theorem for discussions of convergence results not at the median see john ledyard 1984 peter coughlin 1984 coughlin and shmuel nitzan 1981 melvin hinich 1977 for earlier work on spatial competition see richard mckelvey 1975 hinich ledyard and peter ordeshook 1972 1973 and the references quoted therein the present paper focuses on the result of convergence rather than on the median voter theorem per se

macroeconomic regime switches and speculative attacks this paper explains a currency crisis as an outcome of a switch in how monetary policy and fiscal policy are coordinated the paper develops a model of an open economy in which monetary policy starts active fiscal policy starts passive and in a particular state of nature monetary policy switches to passive and fiscal policy switches to active the probability of the regime switch is endogenous and changes over time together with the state of the economy the regime switch is preceded by a sharp increase in interest rates and causes a jump in the exchange rate the model predicts that currency composition of public debt affects dynamics of macroeconomic variables furthermore the model is consistent with evidence from recent currency crises in particular small seigniorage revenues

delaying the inevitable interest rate defense and balance of payments crises the classical model of balance of payments crises implicitly assumes that the central bank sits passively as international reserves dwindle in practice however central banks typically defend pegs aggressively by raising short term interest rates this paper analyzes the feasibility and optimality of raising interest rates to delay a potential bop crisis interest rate policy works through two distinct channels by raising demand for domestic interest bearing liquid assets higher interest rates tend to delay the crisis higher interest rates however increase public debt service and imply higher future inflation which tends to bring forward the crisis we show that under certain conditions it is feasible to delay the crisis but raising interest rates beyond a certain point may actually hasten the crisis a similar nonmonotonic relationship emerges between welfare and the increase in interest rates it is thus optimal to engage in some active interest rate defense but only up to a certain point i

collapsing exchange rate regimes shocks and biases abstract patterns in domestic credit creation stemming from inconsistent fiscal policies have received widespread attention for their role in aggrevating speculative attacks on central bank foreign exchange reserves and contributing to the collapse of exchange rate regimes this paper acknowledges the importance of monetary and fiscal discipline but also emphasizes the importance of other random shocks to the domestic money market most notably shocks from external credit supplies and relative prices policies of the domestic fiscal authorities are only partial catalysts for speculative attacks on a currency expansion of domestic credit stemming from the monetization of fiscal imbalances may be dominated by involuntary domestic credit expansions which are necessitated by surprise shortages in supplies of external capital further the unexpected availability of external capital translates into a lower net critical reserve floor making the depletion of central bank reserves by a speculative attack more difficult to accomplish relative price shocks also randomize the demand for nominal money balances and therefore may also have a strong direct influence on the probability of an exchange regime collapse empirical studies of exchange rate crises that neglect these considerations will produce biased estimates of both expected collapse probabilities and anticipated post collapse exchange rates

competition and integration among complements and network market structure this article analyzes the competition and integration among complementary products that can be combined to create composite goods or systems the model generalizes the cournot duopoly complements model to the case in which there are multiple brands of compatible components it analyzes equilibrium prices for a variety of organizational and market structures that differ in their degree of competition and integration the model applies to a variety of product networks including automatic teller machines real estate multiple listing services and airlines crs as well as to nonnetwork markets of compatible components such as computer cpus and peripherals hardware and software and long distance and local telephone services copyright 1992 by blackwell publishing ltd

a critical evaluation of exchange rate policy in turkey abstract this paper reviews and critically evaluates the exchange rate policy followed in turkey in the post 1980 period during which a far reaching program of liberalization has been launched we conclude that the new exchange rate policy has been essential for turkey s regaining its creditworthiness furthermore it has positively contributed to growth of output and exports and to expansion of tradables production relative to nontradables persistence of inflation and weakness of private investment in tradables overshadow the successes recorded in other areas and cast doubt over the sustainability of turkey s outward orientation we argue that the root cause of these problems has been inconsistencies between overall economic policies rather than the exchange rate policy itself we compare the period of real appreciations since late 1998 with the earlier period of real depreciations and draw policy implications

determinants and costs of current account reversals under heterogeneity and serial correlation using large panel data sets for analysis of determinants and costs of reversals asks for controls of latent heterogeneity among countries this article performs a bayesian analysis which allows for a parsimonious yet flexible handling of country specific heterogeneity via random coefficients and serially correlated errors consideration of persistence within the employed macroeconomic data is important to gauge the impact of explaining variables suggested by theory correctly bayesian specification tests provide evidence in favour of models incorporating heterogeneity and serial correlation the results suggest that costs of reversals are overestimated when country specific heterogeneity is neglected and stress the importance of external variables in explaining current account reversals results are checked for robustness against the underlying reversal definition

libre software turning fads into institutions the article presents an economic analysis of libre software and of its sustainability as a new economic model for software we underline the role of libre software development communities and analyze incentives for both kernel and obscure developers we emphasize the role of the so called public licenses to provide an appropriate institutional framework we show that several features of libre software also allow it to improve faster than proprietary software and therefore to achieve strong market performance when competing against existing standards even when proprietary software producers react we illustrate our point using a simple local and global interaction model to study the technological competition between linux and windows on the server operating system os market we finally argue that if sufficient initial momentum could be created through public intervention libre software could turn from a fad into an efficient economic institution to correct inefficiencies due to network externalities

currency crashes in emerging markets an empirical treatment we use a panel of annual data for over 100 developing countries from 1971 through 1992 to characterize currency crashes we define a currency crash as a large change of the nominal exchange rate that is also a substantial increase in the rate of change of nominal depreciation we examine the composition of the debt as well as its level and a variety of other macroeconomic factors external and foreign crashes tend to occur when output growth is low the growth of domestic credit is high and the level of foreign interest rates are high a low ratio of fdi to debt is consistently associated with a high likelihood of a crash

learning large deviations and recurrent currency crises this article studies a version of obstfeld s journal of international economics 43 1997 61 77 escape clause model the model is calibrated to produce three rational expectations equilibria two of these equilibria are e stable and one is unstable dynamics are introduced by assuming that agents must learn about the government s decision rule it is assumed they do this using a stochastic approximation algorithm it turns out that as a certain parameter describing the sensitivity of beliefs to new information gets small the algorithm converges to a small noise diffusion process the dynamics of exchange rate changes are then characterized using large deviation techniques from freidlin and wentzell random perturbations of dynamical systems second edition berlin springer verlag 1998 these methods describe the sense in which the limiting distribution of exchange rate changes is approximated by a two state markov switching process where the two states correspond to the two e stable equilibria the model is calibrated to the exchange rate histories of argentina brazil and mexico currency crises in these countries resemble the predicted escape routes of the model a key feature of these escape routes is that expectations of a devaluation erupt suddenly without large contemporaneous shocks this is consistent with evidence showing that crises are often poorly anticipated by financial markets

gold monetization and gold discipline gold and its price have emerged as frequent topics of both academic and government debate 2 public attention focused on the gold market since gold s price began fluctuating violently in 1980 and 1981 has turned to gold as a possible means of removing some discretion inherent in the current fiat money system since lack of adherence to monetary rules can lead to problems of dynamic policy inconsistency academic economists have begun seriously to reconsider monetary standards based either on gold or on some other commodity as politically feasible methods of establishing rules 3

explaining the duration of exchange rate pegs abstract this paper is an empirical investigation of the duration of exchange rate pegs in 16 latin american countries and jamaica we identify factors that influence peg duration using logit analysis the real exchange rate and the level of international liquidity are significant determinants of the monthly likelihood of devaluation structural variables such as the openness of an economy and its geographical trade concentration and political variables such as changes in the executive also significantly affect the likelihood of a devaluation there is some evidence that the likelihood of a devaluation first rises and subsequently declines during the first year of a peg

reserve accumulation and financial crises from individual protection to systemic risk abstract this paper provides a new perspective on the relationship between countries international reserve holdings and financial crises while the local view holds that reserves may prevent domestic crises it overlooks that the accumulation of reserves relaxes the financing constraint of the reserve currency country and may cause a financial crisis in the centre which is transmitted globally according to this global view reserve accumulation might destabilize the international financial system since the crisis affects all countries alike the accumulation of reserves imposes a negative externality on non accumulating countries we integrate this idea in a theoretical model of the optimal amount of reserves and illustrate the gap between local and global optimality the consideration of systemic risk lowers the demand for reserves moreover if a supranational authority determines the optimal level of reserves it internalizes the negative externality and accumulates fewer reserves a macroprudential tax on reserve hoardings might implement the socially optimal solution our calibration analysis shows that these considerations are economically significant they lower the optimal amount of reserves in the benchmark case by 45

the use of the exchange rate for stabilization a real interest arbitrage model applied to argentina we model interest rate and portfolio determination under the risk of real currency devaluation taking into account risk aversion on the part of investors a simple extension of the friedman savage analysis of consumer behavior under uncertainty to a two period two country setting allows us to explicitly solve for the interest rate premium paid in the risky asset the model is applied to the 1979 1980 argentinean experiment with the pre announced exchange rate empirical results suggest that a safety factor central bank reserves as a fraction of m2 is closely related to the net ex ante and ex post arbitrage differentials in favor of argentina relative to the united states jel d8

financial policy and speculative runs with a crawling peg argentina 1979 1981 abstract in this paper we present a model of a balance of payments crisis and examine the argentine experiment with a crawling peg between december 1978 and february 1981 the approach taken allows us to examine the evolution of a crisis when a collapse is not perfectly foreseen and yields plausible estimates of one month ahead probabilities of a collapse of the crawling peg the results suggest that the viability of an exchange rate regime depends on the consistency of exchange rate policy with domestic credit policy if the two are not consistent confidence in exchange rate policy is undermined

currency crises with the threat of an interest rate defence while virtually all currency crisis models recognise that the decision to abandon a peg depends on how tenaciously policy makers defend it this is seldom modelled explicitly we add the threat of an interest rate defence to the global game model of morris and shin american economic review 88 1998 with an endogenous defence actions of speculators may become strategic substitutes instead of the usual complements nevertheless our generalised model remains tractable and has a unique threshold equilibrium it provides additional insights for instance the threat of an interest rate defence makes speculation riskier and this may be sufficient to keep speculators out when fundamentals are still relatively strong

the international monetary system forty years after bretton woods review essay in may 1984 a distinguished group of central bankers and economists gathered for a conference at bretton woods to consider the evolution of the world monetary system that was born at that location forty years earlier this volume contains nine essays with accompanying discussion on issues of performance and reform of current international monetary arrangements these papers deal with problems facing the industrialized and the lessdeveloped countries and assess the institutions that have been set up to accommodate these problems the major accomplishments of the original bretton woods conference were of course the establishment of the system of payments based on fixed exchange rates and the organization of the world bank and the international monetary fund as the order developed in the late 40 s and early 50 s each central bank saw it as its duty to intervene in foreign exchange markets to ensure an essentially fixed parity of their currency with respect to the dollar the role of the u s was to guarantee the dollar price of gold at 35 an ounce the system has been called a dollar standard because the dollar played the role of a reserve currency one of the paradoxes of the system as robert triffin pointed out in the early 60 s is that in order to produce a continuing and rapid enough expansion of world reserves the u s had to run balance of payments deficits yet continued deficits by the u s threatened the convertibility of the dollar into gold as it happened the system of fixed parities broke down in the early 70 s not because of a lack of reserves but because a glut of dollars made the bretton woods dollar exchange rates untenable the system eventually evolved into one in which most of the industrialized countries currencies more or less are determined by the market while the currencies of most second and third world countries are pegged to a major currency the floating period has been

collapsing exchange rate regimes some linear examples abstract we construct a pair of linear examples to study the collapse time of a fixed exchange rate regime the first example is a perfect foresight continuous time model which allows calculation of the exact collapse time and the tracking of reserves the second example is a discrete time stochastic model which yields an endogenous probability distribution over the collapse time and produces a forward discount of the exchange rate

a model of corporate donations to open source under hardware software complementarity in recent years there has been an increasing diffusion of open source projects as well as an increasing interest among scholars on the topic open source software oss is developed by communities of programmers and users usually sponsored by private firms is available in the public domain and redistributed for free we present a model of open and closed source software competition in a differentiated oligopoly of hardware software bundles hardware and software are complement goods and oss is financed by hardware firms results are several hardware firms contribute to the development of open source although the level of contribution is not socially optimal oss availability has a positive impact on hardware firms profits and prices whereas the closed source producer is harmed by oss competition furthermore we analyze under what circumstances hardware firms have incentives in investing in os projects the model can explain the increasing participation in os projects of several embedded device producers and server producers although we focus on hardware this model can be generalized to a wide range of complementary goods and services such as it training web hosting and information and communication technology ict consultancy services

the exact timing of the collapse of an exchange rate regime and its impact on the relative price of traded goods as of february 28 1983 ninety four countries are classified as having a fixed exchange rate regime 38 are pegged to the u s dollar 13 to the french franc 14 to the special drawing right and 24 to different baskets of currencies the choice of a fixed exchange rate peg implies a specific monetary discipline namely monetary growth equal to the growth rate of the currency or currencies to which a country is pegged monetary policy is thus subject to an exchange rate rule rather than to either a monetary growth rule or alternatively to discretionary policy a fixed exchange rate is a specific case of an active crawling peg where the preannounced rate of change in the exchange rate is zero active crawling peg rules whereby the exchange rate is adjusted downward by a preannounced amount over a specified period of time have been practiced in various places particularly in latin america recent experiments include argentina beginning december 1978 brazil during the 1980 calendar year chile from february 1978 to june 1979 jamaica from may 1978 to may 1979 portugal from august 1977 to june 1979 and uruguay beginning october 1978 1 at times the prean

the lifetime of a unilateral target zone some extended results abstract in dumas and svensson journal of international economics 36 1994 467 the lifetime of a krugman quarterly journal of economics 106 1991 669 682 type target zone model is found to be extremely long this paper shows that the lifetime of the identical target zone regime can be much lower when real disturbances occur in particular the mean lifetime is found to be very low when real disturbances occur and the real exchange rate elasticity of the demand for domestic goods is very low it is also shown that allowing for monetary disturbances to have real effects has very little effect on the lifetime the results indicate the conditions under which real disturbances might trigger currency crises

bank firm relationships and contagious banking crises this paper argues that in an open economy a banking system with close bank firm relationships may be easily subject to contagious banking crises because it is difficult to distinguish between crony capitalism and good main bank relationships 1 show that if international investors cannot distinguish the bank type the distinction between crony capitalism and good main bank relationships becomes very fuzzy in particular the model can explain sequences of bank defaults within a country even if the insolvent banks are very few ex ante as well as sequences of banking crises among countries that are equally rated by international investors but indeed differ in the ex ante solvency of their banking system