Experimental abatement data of underflow baffles for removal of floatables in the CSOs of the Greater Montréal (Canada) area.

Underflow baffles have gained in popularity over the years as a viable mean to intercept floatables in Combined Sewer Overflows (CSOs). This choice was mainly justified by the extremely low capital cost (CAPEX) and operational cost (OPEX) of this solution, although the efficiency of underflow baffles has never been clearly proven. The only similar application to underflow baffles are scum boards in grit chambers and clarifier. However, the flow conditions at CSOs vary considerably from those in grit chambers and clarifier. For this reason, review of the behavior of floatables in a rapid flow is paramount. Only then can comprehensive design criteria for underflow baffles and overflow chambers be suggested. Pilot scale tests, performed in a 17 metres long basin at various flowrates, had already shown that a critical horizontal velocity for floatables (Vcr) may develop in the overflow chambers. In this follow up study, the fate of intercepted floatables was investigated. It appears from this latest data that permanent capture of floatables decreases rapidly with an increase in the horizontal velocity of the flow, no matter what the baffle depth. Baffle depth increases capture at lower velocities (0.17 m/s) but become irrelevant at higher velocities (0.61 m/s). This data suggests that capture efficiency of existing underflow baffles in overflow chambers can be, at best, very low whenever the horizontal velocity increases above 0.30 m/s or 1 ft/s.     

EFFECT OF FED POLICY ACTIONS ON THE DEFAULT LIKELIHOOD OF COMMERCIAL BANKS

Using a measure of default likelihood based on an option pricing method, we provide evidence that Fed policy actions affect the financial distress of commercial banks. When the Fed increases (decreases) interest rates, the measure of default likelihood increases (decreases). We show that when the Fed uses a tight money policy, the increase in default likelihood is more pronounced for banks that have less capital, have greater financial leverage, are smaller, have fewer growth opportunities, and have lower asset quality. Additionally, the effects on bank default likelihood are more pronounced when the Fed's policy signals less concern about economic growth, as indicated by its bias toward further tightening, and when there is a market expectation of higher short‐term market rates in the future.     

The Politics of Housing Unmasked

Proposed economic reforms often neglect to take into account the interests of groups which have benefitted from establishing or maintaining the status quo. Martin Ricketts, Reader in Political Economy at the independent University of Buckingham, assesses the political pressures that have produced regulation of the housing market, and suggests reform which accommodates realistic expectations of resistance from local politicians and subsidised tenants.     

General‐to‐Specific Model Selection Procedures for Structural Vector Autoregressions*

Structural vector autoregressive (SVAR) models have emerged as a dominant research strategy in empirical macroeconomics, but suffer from the large number of parameters employed and the resulting estimation uncertainty associated with their impulse responses. In this paper, we propose general‐to‐specific (Gets) model selection procedures to overcome these limitations. It is shown that single‐equation procedures are generally efficient for the reduction of recursive SVAR models. The small‐sample properties of the proposed reduction procedure (as implemented using PcGets) are evaluated in a realistic Monte Carlo experiment. The impulse responses generated by the selected SVAR are found to be more precise and accurate than those of the unrestricted VAR. The proposed reduction strategy is then applied to the US monetary system considered by Christiano, Eichenbaum and Evans (Review of Economics and Statistics, Vol. 78, pp. 16–34, 1996) . The results are consistent with the Monte Carlo and question the validity of the impulse responses generated by the full system.     

Competition and structural change in Eastern Europe

Widely publicized reform programs for East Europe which emphasize rapid privatization are questioned on the grounds that structural changes to assure workable competition take precedence and will take years. A mix of deconcentrated state, cooperative, worker-owned, private, and foreignowned business can be workable. Import competition and antitrust legislation have auxiliary roles.     

Competitive and Information Effects of Cross-Border Stock Listings

We examine the effect of 269 cross‐border listings on rivals in the listing and domestic markets and find that U.S. rivals experience significant gains whereas domestic rivals do not. Both competitive and information effects are important in explaining the reaction of U.S. rivals. Regarding the competitive effects, the reaction of rivals is less favorable when listings originate in developed countries and more favorable when listing firms do not have prior operating presence in the United States. Regarding the information effects, the reaction is less favorable when listings are combined with equity offerings and more favorable when the listing is the first to occur within an industry.     

The recent failure of U.S. monetary policy

Summary The very slow growth of the broad money supply has been a primary source of U.S. economic weakness in 1990 through 1992. The velocity link between M2 and the subsequent level of nominal GDP has not declined. But changes in bank reserves brought about by open market operations have had much less effect onM2 than the Fed anticipated for two reasons: (1) reserve requirements now apply to only a small fraction of totalM2; and (2) the new bank capital requirements limit some banks ability to lend. The Federal Reserve failed to appreciate the importance of these conditions and misjudged the strength of the monetary policy stimulus that it was providing.Professor of Economics, Harvard University, and President of the National Bureau of Economic Research.Sixth Tinbergen Lecture delivered on October 2, 1992, in The Hague for the Royal Netherlands Economic Association.