International aid is rather broad as a term, and means many things to many people. It can be broken into three rough categories: emergency or humanitarian aid, non-governmental organization (NGO) -sourced or charitable aid, and government to government aid. Humanitarian aid is often characterized by water and food shipments, doctors and surgeons, building materials, and other things that are needed in the aftermath of a natural disaster or other similar calamity. Charitable aid is often characterized by (usually small) local projects to install wells, sanitation facilities, or to give out free vaccinations. Finally, government to government aid is often in large chunks, with strings attached ("earmarked" for certain things, or `you must buy 20% of the supplies from a corporation in the donor country`), and for much bigger ticket items like roads, dams, and just generally infrastructural or capacity-building improvements. These categories are pretty fuzzy and some projects can span all three, but they serve as reasonable markers for the different types of aid. In light of these categories, I'll do my best to represent the arguments in favor of, and against, aid, faithfully, and finish with my own conclusions about the current state of international aid and whether or not it's a worthwhile enterprise.
Aid is historically a complicated topic because it stems directly from colonial powers and their attempts to develop their colonies, and though anecdotal it is exemplary that the Oxford Department of International Development (from which many fine development practitioners originate) was, originally, The Institute of Colonial Studies (Clary). More recently, international aid to and development of "The Global South" (née the third world) have been inextricably linked, as the United Nation's Millennium Development Goals (MDG's) put much of the world on notice to reduce infant mortality rates, rates of extreme poverty, and to put all children through primary school (among other goals, there are 8 total), and it has been broadly seen as necessary for everyone to pitch in, if they can. It has been argued that aid is one part of the path to achieving these goals.
In favor of aid, one looks back at many of the metrics associated with underdeveloped nations, and how they have improved significantly (and indeed faster than the developed nations in some cases) for evidence of aid having a wonderful impact on nations. John McArthur at Intelligence2 points out that one of the largest criticisms about aid destined for the African continent is that it's all squandered through bad governments with bad governance practices (which is to say, corruption), whereas he points out the slow growth on the continent (2% slower than any governments with equivalent Transparency International scores) is more due to disease, lack of critical infrastructure, a lack of education, and a terrible legacy of colonialism. He further points out a laundry list of successes of aid, including the eradication of smallpox, the elevation from 50k (2002) to 1m (2007) people receiving anti-retro-viral drugs to fight HIV/AIDS, primary school enrollment rates up 20% since 1991, and that measles deaths were cut by 91% between 2000 and 2006 (4 years ahead of schedule). Additionally, C. Payne Lucas, at the same event, remarked on the fantastic progress a not-insignificant number of nations have made, that "we have 16 or 18 countries which have track records of doing well" due to, and with, aid. He further points out great research which was done into river blindness, that now allows millions of acres to be accessed that were previously inaccessible. Further, he makes a moral argument that it's on us to help those African governments who truly are making a good faith effort to improve their countries, such as the then-newly-elected president of Liberia. He argues that we have an opportunity to do well for Africa, so we must do it – and that these aid projects we undertake must be owned by Africans, African led, sustainable, and accountable. He says if we don't help out Africa, we'll have a terrorist problem on our hands. Jeffrey Sachs is also strongly in favor of aid, citing Kenya's plummeting infant mortality rates (as a result of mosquito nets being deployed). He cites the success of the MDG's in prompting collective aid projects going into Africa to quell the aforementioned problems with HIV/AIDS, malaria, and additionally Tuberculosis. Sachs also points to debt forgiveness programs as crucial to allowing governments to support their budding healthcare services (and thus alleviating the disease/healthcare problems themselves). Our aid to the African continent for healthcare has risen by around $1b per year since 1995 (7.9b → 26.9b, in 2010), and he argues this has gone hand in hand with decreases in infant mortality rate (12m/y in 1990 → 7.6m/y in 2010) and reductions in malaria deaths from (1m/y in 2004 → 700k/y in 2010). The arguments in favor of aid are pretty convincing, as far as hard change goes, especially in the healthcare arena.
Against aid, however, stands Dambisa Moyo, with equally impressive statistics, however in the opposite direction of Sachs, McArthur, and Lucas. She cites that in 1970 there was a 10% poverty rate on the continent of Africa, and now there is a 70% rate (Moyo, HardTalk). In her view, everything has been getting better in spite of aid, not because of it, and she can find no direct correlation between aid and improvement in most countries. She draws a correlation between aid and corruption, because (to paraphrase) there's nothing preventing corruption, people will be fed by food aid dollars (Moyo, HardTalk). Moyo lays out the top reasons, for her, that aid isn't working: corruption, inflation (monetary exchange rates and bad fiscal policy) and debt burdens of the government, what she calls "dutch disease" (outside currency floods the market, making local currency scarce and thus valuable, resulting in exports which are too expensive which kills demand for them), dead entrepreneurship due to aid (people get lazy because they know aid will always be there), and aid having a disenfranchising effect on Africans because the elected leaders court aid agencies and not their constituents. She also finds a strong linkage between aid and civil war and unrest, with groups vying for control over government and thus access to the aid money (Moyo, Why). The good news of the argument she makes is that we're merely not using our own tools to solve the problem. She says that we in the West are espousing certain beliefs and systems in the West, and then going to Africa and telling the leaders to do something else. So, Moyo suggests that increased trade, Foreign Direct Investment, micro-finance, and remittances are good tools to help. Moyo also looks to the model of the BRICS countries and how they have been doing development, which is in 5 year plans, with explicit, transparent, verifiable goals. She cites two specific examples where this happened and worked fantastically, which are the Marshall Plan (done by the US after World War 2 to assist rebuilding Europe), and Botswana. She thinks it's futile to fight at the World Trade Organization against countries like the US for more favorable trade deals, when African nations could sell their produce to China (who would be giddy to buy it, and who "would not bother with questions of democracy and good governance"). Taken together, this paints a rather bleak picture of aid, and she (better than I can do in one page on the topic) puts in stark relief how weak the correlations are between aid and improvement in African nations.
As for my view on international aid and what effect it has, if any: I am against the continuance of aid. I like the 5 year plan concept, because it allows for testable results (reduce X by Y% in 10 years), but I do have qualms even with that. I have large issues with both approaches, those for aid because of the rosy outlook and self justifying rhetoric that never seems to be quite able to correlate improvement on the ground directly with aid, and Moyo's anti-aid stance because it's still a free market neoliberal capitalist approach (which is, at best, incredibly problematic). Moyo's stance is better than those for aid, in that her plan is less harmful to Africans than aid is, but setting the bar at "not quite blatant colonialism" isn't setting it very high. I draw upon complexity theory (and a little post-colonial critique) for my argument. Aid, as it is implemented (and as it is likely to be implemented, even with reforms) does very little to help developing nations. It distorts markets – commodity, currency, and agriculture alike, preventing them from being on anything close to an even playing field with the rest of the world. Targeted interventions, without capacity-building, are worthless (Taylor, Complexity Theory in International Development). They "fix" a problem with outside help, but for example if the elimination of TB on the African continent does not go hand in hand with well developed healthcare systems in those countries (and all the prerequisite services, public and private, which make healthcare systems work well), it will end up being wasted money because of reinfection or relapse. Ebola is currently spreading across western Africa at an ever-increasing clip due to both a lack of developed healthcare systems and a lack of educational systems.
I agree with some of Moyo's critiques (if not her solutions), in that aid tends to create a vicious cycle of dependency that's nigh impossible to work a nation out of. Ghana had mismanaged their own development projects in the early 1990s, and by the early 2000's needed outside help, which they took in the form of Structural Adjustment Loans from the International Monetary Fund. These were a disaster, requiring austerity in government services, privatization of public goods such as water distribution, and slowing the growth of the country in the pursuit of paying back loans. After 5 years, Ghana's government decided to reject the privatizations and continue to pay back the loans, except with a priority on their people and not the loan originators (Taylor, Complexity Theory and the Failures of Neoliberal Development in Ghana). This has worked quite well for them. I firmly believe that if we stopped standing on Africans' throats, they could develop the systems they need completely without aid.