Marshall-Lerner Condition and J-Curve

The Marshall-Lerner condition states that a country's depreciation/devaluation on its currency will cause exports to increase, imports to decrease, and thus an improvement in its current account (usually from deficit to surplus).  For this to occur, PED of exports plus PED of imports must be greater than one (because demand needs to be elastic for the process of going from deficit to surplus to work...think logically).  Here is the J-curve which simply shows this condition graphically:

The J-curve shows us what would happen over time if a government devalued/depreciated its currency over time.  As first, because the value of the currency would be immediately lowr, the capital account would actually worsen as less money would come in for exports.  This is the downward-sloping part of the J-curve.  However, over time, foreigners would notice these exports are cheaper and the domestic consumers/firms would notice imports were more expensive, so the balance of trade would improve theoretically until the deficit was replaced by a surplus (moving up the curve to the right).