Interdependence
Does it matter for policy design?

Over the past decade, the annual economic summit meetings have shown that Western policy-makers are as yet unable to design and operate a viable programme of coordinated economic policies, even though they are fully aware of the mutual dependence of their economies.

Economic theory has explored the transmission mechanisms between economies, policy effectiveness and interdependence, and the potential gains from coordination. But few theoretical models describe how interdependence should affect policy design, or are even able to determine the signs of the net policy 'spillovers' between economies. In Discussion Paper No. 108, Research Fellow Andrew Hughes Hallett analyses interdependence among the main OECD countries and how recognition of this interdependence would affect policy design. Hughes Hallett uses the EEC Commission's COMPACT forecasting and policy analysis model to evaluate how the 1977-81 policies of the world's three main industrial blocks, the United States, the EEC and Japan, would have been affected had these policies taken into account spillovers and feedbacks from abroad. The research in this Discussion Paper is related to other work by Hughes Hallett, described in Discussion Paper No. 77 and at a January lunchtime meeting addressed by Hughes Hallett, reported in Bulletin Nos. 12 and 13 respectively.

Hughes Hallett's policy simulations of the COMPACT model are conducted in the framework of a dynamic game, in which the various countries act and react to each other's policies through time. The effects of interdependence on policy can be measured by considering the behaviour of a range of policy rules which take account of interdependence in varying degrees. These range from the benchmark solution, in which policy is formulated taking full account of interdependence, to the 'myopic' policy, which ignores all spillovers and policy feedbacks.

Hughes Hallett's simulations suggest that for the EEC, the net spillovers are small and are hardly modified by feedbacks or counter-measures abroad. Expansionary policies abroad have a small positive effect on EEC investment, employment, and the balance of trade. The international transmissions affecting Europe appear to operate through income and monetary linkages, rather than through changes in the terms of trade. The simulations suggest that interdependence is also relatively unimportant for policy-making in the United States. Expansion abroad has a positive effect on output, which arises mainly through a larger US trade surplus, but has little effect on inflation or unemployment.

Japanese policy-making, on the other hand, is sensitive to interdependence in the simulations. Expansion abroad causes negative spillovers on output and employment through a deteriorating trade balance. That contractionary pressure permits a reduction in government borrowing; the reduced foreign exchange reserves are used to restrict monetary growth at comparatively low interest rates. The outcome is therefore lower inflation.

The insensitivity of the EEC and US policies to spillovers and feedbacks indicates that net spillover effects are small, even though some are quite large individually. This may occur because the spillovers between two countries offset each other; for example, EEC and US expansion had negative spillover effects on Japan and this will offset any positive spillovers which a Japanese expansion could otherwise have had on the United States or the EEC. Hughes Hallett also notes that different policy instruments used by one country can have offsetting spillover effects on a foreign economy. Finally, Hughes Hallett observes that policy rules may be insensitive to spillover effects, even though the economies concerned are sensitive to them. This would happen if the spillovers from abroad on one domestic policy target called for a policy instrument to be adjusted in one direction, while the spillovers on another target call for the opposite adjustment to that instrument.

Hughes Hallett's simulations also suggest that US policies are substantially more vigorous than those in Japan or the EEC. The variability of US policy instruments is two to three times higher than their EEC counterparts in the simulations. Even the Japanese policy instruments (social security contributions excepted) are used more vigorously than their EEC counterparts. This may suggest a greater flexibility of the US economy, because the responses to each vigorous policy change must have been sufficiently large and quick to warrant making those changes. This is not true for the EEC, where policy instruments were adjusted less vigorously. Hughes Hallett suggests that this lack of flexibility in the European economies may go a long way to explaining their poor economic record compared to the United States and Japan, and why it has proved so much more difficult to start a recovery and overcome unemployment in the EEC economies.

It has often been suggested in the popular debate that the performance of the world's economies would be improved if they followed parallel (if not identical) policies. In this context, some economists have suggested that European governments should accept greater fiscal expansion in return for reduced US budget deficits.

Hughes Hallett describes two simulations of 'harmonization': the first, in which the EEC tightens its monetary policy and expands in fiscal terms (to match US policies), and the second, in which the United States tightens its fiscal policies and budget while expanding its monetary position (to match EEC policies).

Under the first policy, Hughes Hallett finds that the only benefit to the EEC would be that growth would increase by 0.5% per annum. Interest rates rise and higher social security contributions are needed to contain the governments' borrowing requirement. The upshot is less investment and, largely as a result of the recession which this strategy induces abroad, higher unemployment in the EEC. This strategy also increases world inflation, so that prices rise faster in the EEC. In fact the EEC 'exports' most of its recession to the United States, where growth falls 0.5%, and inflation rises 1%, because US policies do not adjust. Japan, on the other hand, switches to direct taxation and more fiscal activity generally. This prevents much loss of growth, but generates a higher trade balance and greater government borrowing.

The second case, of fiscal restraint and more relaxed money in the United States, is more favourable. The EEC grows faster, and no longer experiences lower investment or higher inflation. Meanwhile unemployment falls an extra 0.5% because of stronger expansion abroad. The United States reacts with much stronger output growth and - for the first time - a marked drop in interest rates. This leads to higher inflation levels. Government expenditures fall somewhat more than receipts, reducing the government's budget deficit. The upshot of these contractions is 0.5% more unemployment but a smaller trade surplus in the United States. Japan experiences a trade surplus as a result of the US fiscal restraint strategy, but is otherwise hardly affected.

The results suggest, according to Hughes Hallett, that there is a case for some convergence of policies. The burden would fall mainly on the United States, since a shift in US policy towards greater fiscal restraint is found to be more effective than moves by the EEC towards tighter monetary policy.


The Impact of Interdependence on Economic Policy Design: The Case of the US, EEC and Japan
Andrew Hughes Hallett

Discussion Paper No. 108, May 1986 (IM)