The rise in global stock prices from early March to mid-June is arguably the primary cause of the surprising positive turn in the economic environment. The $12,000bn of newly created corporate equity value has added significantly to the capital buffer that supports the debt issued by financial and non-financial companies. Corporate debt, as a consequence, has been upgraded and yields have fallen. Previously capital-strapped firms have been able to raise considerable debt and equity in recent months. Market fears of bank insolvency, particularly, have been assuaged.

Is this the beginning of a prolonged economic recovery or a false dawn? There are credible arguments on both sides of the issue. I conjectured over a year ago on these pages that the crisis will end when home prices in the US stabilise. That still appears right. Such prices largely determine the amount of equity in homes – the ultimate collateral for the $11,000bn of US home mortgage debt, a significant share of which is held in the form of asset-backed securities outside the US. Prices are currently being suppressed by a large overhang of vacant houses for sale. Owing to the recent sharp drop in house completions, this overhang is being liquidated in earnest, suggesting prices could start to stabilise in the next several months – although they could drift lower into 2010.

In addition, huge unrecognised losses of US banks still need to be funded. Either a stabilisation of home prices or a further rise in newly created equity value available to US financial intermediaries would address this impediment to recovery.