(seekingalpha.com) If you have been following what we have been writing you will know that we have become bullish on oil (NYSEARCA: USO ) prices for the next few years.

As with most of our opinions we have arrived at this one by listening to what some of the world’s best investors are saying about oil and why they are saying it.

We believe that Jeremy Grantham is another voice worth paying attention to, and it turns out that he too believes oil is going higher, perhaps significantly so. Source: GMO.

Grantham: Oil Is Going Higher; Here’s Why

In Grantham’s most recent quarterly report to investors he had the following to say about oil and why he believes it is headed higher.

Reason #1 – Shale Oil Is Relatively Small In Scale U.S. fracking oil is a small resource, under one and one-half years of global consumption. It will soon run off and show the underlying implacable rising costs of finding ever-diminishing pools of new oil. Reason #2 – Higher Rates Of Depletion Existing oil wells deplete faster than they used to because enhanced technologies squeeze more into the early years. Over 5 million barrels a day out of a global total of 95 a year now needs to be replaced every year. Half a new Saudi Arabia! Reason #3 – Huge Capital Spending Cutbacks Today’s draconian cutbacks in exploration almost guarantee another sharp price spike in the next two to four years. The Evidence Supports Grantham’s Points Grantham’s points all make a lot of sense when you check into the facts behind them. Here is what we found when we did just that.