(Sharecast News) - In his 'Inside the City' column for the Sunday Times this week, Tommy Stubbington claimed Ashtead was one of the many beneficiaries of the so-called 'sharing economy' - even if the notion of a sharing economy doesn't usually consist of diesel-powered generators and cement mixers.The Surrey-based building equipment rental form was booming until last autumn, when it was caught up in the global sell-off, which itself was prompted by fears the US economy was headed for a recession.Stubbington said Ashted was particularly exposed to any negative sentiment around construction in the US, given around 85% of its sales came via its American operation, Sunbelt.But the doom and gloom surrounding the world's largest economy has largely lifted now, thanks to rhetoric from the Federal Reserve that it would slow down in its plans to hike interest rates.That meant that for Ashtead, given its relatively strong set of interim numbers in December, not much had changed apart from a significant discount in its share price.Investors were looking towards its third-quarter update this week, Stubbington said, with the firm expecting further growth in its revenue and profits.Broker Bank of America Merrill Lynch has forecast a 23% improvement in Ashtead's pre-tax profits for this year, to £1.1bn, with a further increase to £1.3bn next year.And looking ahead, Stubbington said it would be a decent bet to assume Ashtead could keep on pocketing profits thanks to the current preference for firms to rent things, as opposed to buy them.Sunbelt is the second-largest firm in the fragmented US plant hire market with an 8% market share, behind the 12% boasted by American Rentals, which could mean that Ashtead's modus operandi of swallowing up smaller competitors and opening new rental depots still had plenty of steam in it.There was still reason for caution, however, given Geoff Dribble - who transformed Ashtead from an "unsexy" plant hire firm in 2006 to a FTSE 100 "powerhouse", was stepping down in May.His replacement, Brendan Horgan, had played a "pivotal role" in Ashtead's transformation too, however, being in charge of Sunbelt since 2011.If US president Donald Trump ever manages to see his promises of giant infrastructure spending through, it could be a boon for Ashtead, but even without that, it could still keep its head well above water so long as the US economy manages to avoid a serious downturn for the time being."The shares have raced back in the new year and closed at 2047p on Friday, valuing the business at £9.7bn, but they are still some way short of last year's peak," Stubbington said."Unless you think a US recession is around the corner, they look like a buy."Over in the Mail on Sunday, Joanne Hart was looking at Emmerson, claiming that the predicted boom in world population to 9.5bn from the current 7.6bn in the next three decades could prove a boon for the potash mining company.All of those extra people will need to eat, and while potash - a potassium compound - is not generally recognised for its nutritional value, it is a vital ingredient in fertiliser - an industry that churns out around 200 million tons of product each year.Hart noted that most potash mines were located in the harsh northern reaches of Russia and Canada, but pointed out that the AIM-traded Emmerson was developing a mine in the much milder Morocco, at a location less than 40 miles from the coast.She said the shares - currently standing at 3.1p - should rise "significantly" as Emmerson moved into production, making use of its location to ship potash much more efficiently to major world markets including Brazil, the southern United States, South Africa and Europe.There was decent potential in the company's home continent, too, with demand for fertiliser in Africa - where the product has not historically been used much - rising by around 30% per year.Morocco was also proving to be a land of opportunity, with OCP Group - one of the globe's largest fertiliser companies - moving from solely focussing on phosphate to producing complete fertiliser products.If it can source potash locally from Emmerson, it would save it needing to import the product, with Emmerson's Khemisset mine situated less than four hours away from OCP's primary production plant.While Emmerson still had several hurdles to clear before it could make money, it did believe it could produce around 800,000 tonnes of potash per year at one of the world's lowest costs, while production was also likely to increase significantly, given the 450 square mile parcel of land it occupies.Chief executive officer Hayden Locke was looking to only make use of a third of that area initially, in a bid to keep costs down, although Hart believed that over time, the company's mining activity there would expand, leading to increased production and a life-of-mine of several decades.Locke was looking to kick off a formal feasibility study in the coming weeks, with costs to bring the mine into production expected to be around £300m - chump change compared to other potash projects.He was also apparently in discussions with a number of potential funders, with the talks seeing interest grow by all accounts.Emmerson was looking to begin commercial production in 2022, with it expected to be "immensely profitable" after operations begin, with the mine expected to generate cash of at least £100m after tax each year.While there remained a risk that potash prices - which have been rising recently - could fall, Hart said Emmerson would still be able to make money after a 20% dip in prices, as its more Siberian peers struggled to keep their heads above water."Locke is also an experienced operator, having brought two mining companies through the development and financing phase in the past decade, one of which was sold for $570m (£430m) in 2014."