Economic expectations can turn around very rapidly. The trick is to work out whether the change is a result of changes of substance in the real world or simply a matter of sentiment – gut reaction if you like. When I wrote my piece for this newspaper for the first week of January I believed that I was at the distinctly bearish end of the spectrum – other forecasters and commentators were more positive than me regarding the UK and Scottish outlook. How that has changed! I now feel that I was being relatively bullish – that rare specimen the economist as optimist.

The change in expectations has been reflected most strongly in the markets. Equities crashed down around the world while oil prices fell further to ten year + lows. The bond markets also felt the impact of the wind of change, in that they priced in continuing low interest rates in the UK and Europe for many a moon – with even some suggestion that the US Federal Reserve might be forced to reverse the increase in rates implemented in autumn 2015. The watchword was ‘gloom’ and whilst there has been some subsequent stabilisation there has not been anything like full recovery.

It is difficult to see the root cause of the change. Certainly we had relatively weak data for Chinese GDP. However, this had been expected for at least most of 2015 – and the official data were on the upside of expectations. (Although belief in the official data is limited!) This Chinese slowdown, alongside fully anticipated and continuing difficulties in a range of other emerging economies, was a good reason for forecasting slower global growth in 2016. But that should have been factored into forecasts and the markets as 2015 progressed. There was no real ‘new news’.

This anticipated global slowdown was one cause of the downward pressure on oil prices. That pressure was exacerbated by the nuclear agreement with Iran, which will result in that mega supplier re-entering the market. But again that should have been the central scenario for oil price analysts. It should not have been a shock/horror surprise causing a downward lurch in prices.

In sum, my overall expectation of the global outlook has not changed during the period the markets slumped. The markets may have been over-priced, so some readjustment downwards may have made sense, but that downward movement could not be justified in terms of any significant change in economic fundamentals.

We have now seen the first estimate of UK GDP growth for the fourth quarter of 2015. Growth of 0.5% in the quarter and 2.2% over the year marked a slowdown as compared to 2014, but still a relatively strong performance as compared to most other developed economies. However, the balance of growth remains a cause for concern. The production sector, mainly manufacturing, declined in Q4 by 0.2% and construction was also down a smidgeon. The overall increase was essentially thanks to the services sector, which increased by 0.7%.

These data will inevitably be subject to revision, but the key trends are as would be expected. Manufacturing continues to suffer and output is now 6.4% lower than when the 2008 recession struck. For so long as China and other key emerging markets remain relatively subdued, while domestic demand in our key European markets remains at best flat, we cannot expect any significant manufacturing recovery.

The UK outlook for 2016 remains decent but by no means over-exciting – and increasingly dependent upon services. That in turn implies a dependency upon the UK consumer who will wish to see continuing growth in real incomes without significant fears that another recession lies ahead.

Overall the IMF’s forecast of 2.2% growth for the UK this year appear fair and reasonable; but the Office for Budget Responsibility may need to mark down its estimates for the economy and the public finances come the March UK Budget. Already the Chancellor has had to delay his sale of HBOS (and also RBS) shares. That will reduce his revenue this financial year and probably next as well. Combined with less bullish input from the OBR he faces a pretty torrid time as he plans Budget 2016.

Unfortunately Scotland does not share the UK’s positive story regarding the service sector but can empathise regarding weakness ahead for manufacturing and construction. Further the continuing and widening impact of much lower oil prices will work through our economy in the year ahead. The latest Scottish Purchasing Managers Index remained weak. The CBI Industrial Trends survey for January showed a fall in output and the sharpest fall in new orders for some 5 years.

The latest GDP data we have are for Q3, when we markedly underperformed the UK. The only bright spot in the data was construction, buoyed by major public sector engineering projects. The latest Construction Industry Training Board survey suggests a sharp deceleration in the sector in Scotland. All-in-all 2016 could prove a very difficult economic year north of the border. We should not under-estimate the extent to which this will be down to the oil and gas sector, including the impact on the supply chain and the effect of major job losses in companies directly and indirectly affected.

Apologies; I may be a relative optimist on the global story but cannot claim the same for Scotland.

Jeremy Peat is visiting professor at the University of Strathclyde's International Public Policy Institute