Key: the contributions correspond to the variation in the share of each GDP component with an opposite sign. For example, the trade balance improved by 4.5% of GDP between 1981 and 1997; the decline in the share of construction investment in GDP over this period contributed 4.5 percentage points to this increase.
Comments on the evolution of French foreign trade often refer to the competitiveness of the economy, its specialisation and its positioning in international markets. While these factors are key to understanding the evolution and composition of trade flows and the trade balance in level, the trade balance as a share of gross domestic product (GDP) follows a different logic: it reflects economic agents’ decisions regarding consumption – therefore saving – and investment.
Indeed, GDP is the sum of consumption, investment and the trade balance. The variation in the trade deficit as a share of GDP is therefore the sum of the change in the investment rate and the change in the consumption rate, also as a share of GDP. Thus, an increase in the investment rate, if it is not offset by a fall in the consumption rate, i.e. if domestic saving do not finance it, must be financed by saving from the rest of the world. This takes the form of a deterioration in the trade balance (leaving aside current account income).
In this post, we use this equality to highlight the drivers of the French trade balance over the past forty years. The results are presented in Chart 1. The blue line shows the change in the trade balance in % of GDP from its 1981 level. The bars show how the different components of consumption and investment contributed to this change. The chart highlights two stylised facts:
(i) Medium-term fluctuations in the trade balance mainly correspond to the investment cycle, which is largely driven by construction investment, both by households and firms.
(ii) The fall in the share of household consumption in GDP since the turn of the 1990s has contributed to raising the trade balance, but has been offset by an increase in the share of government consumption since the 2008 crisis.
It may seem surprising that price competitiveness does not play a direct role in this decomposition. The reason is that, for a given rate of investment and consumption, a rise in competitiveness certainly increases exports and the level of the trade balance, but leaves the trade balance as a share of GDP unchanged because it also raises GDP. Conversely, a decline in the rate of investment and consumption raises the trade balance as a share of GDP, but lowers imports and the level of GDP, unless competitiveness increases simultaneously.
Competitiveness gains can therefore make it possible to adjust the trade balance without weighing on growth. In addition, they can also have an indirect effect on saving and investment decisions. For example, a depreciation in the real exchange rate may lead to a temporary increase in the saving rate, and thus in the trade balance, if the additional income generated by exports is not immediately consumed.
The remainder of the post addresses in more detail the periods of increase, decrease and stabilisation of the trade balance.
Improvement in the trade balance from 1987 to 1997: higher saving and construction crisis
Between 1987 and 1997, the trade balance improved by 4% of GDP, climbing from -1 to 3% of GDP. Two dynamics were at work behind this improvement.
First, the rate of household consumption declined lastingly from the end of the 1980s (Chart 1, red bars). This rate depends in turn on the share of household income in GDP and on the household saving rate (Chart 2). The improvement in the trade balance was mainly driven by the rise in the saving rate at the turn of the 1990s, even if the smaller share of household income in GDP also played a role.