Introduction

Africa :: Zambia

Background:
The territory of Northern Rhodesia was administered by the [British] South Africa Company from 1891 until it was taken over by the UK in 1923. During the 1920s and 1930s, advances in mining spurred development and immigration. The name was changed to Zambia upon independence in 1964. In the 1980s and 1990s, declining copper prices, economic mismanagement and a prolonged drought hurt the economy. Elections in 1991 brought an end to one-party rule, but the subsequent vote in 1996 saw blatant harassment of opposition parties. The election in 2001 was marked by administrative problems with three parties filing a legal petition challenging the election of ruling party candidate Levy MWANAWASA. MWANAWASA was reelected in 2006 in an election that was deemed free and fair. Upon his abrupt death in August 2008, he was succeeded by his vice president, Rupiah BANDA, who subsequently won a special presidential byelection in October 2008. Michael SATA was elected president in September 2011.

Geography

Location:
Southern Africa, east of Angola, south of the Democratic Republic of the Congo

Geographic coordinates:
15 00 S, 30 00 E

Map references:
Africa

Area:
Total: 752,618 sq km
Country comparison to the world: 39
Land: 743,398 sq km
Water: 9,220 sq km

Area - comparative:
slightly larger than Texas

Land boundaries:
Total: 5,664 km
Border countries: Angola 1,110 km, Democratic Republic of the Congo 1,930 km, Malawi 837 km, Mozambique 419 km, Namibia 233 km, Tanzania 338 km, Zimbabwe 797 km

Coastline:
0 km (landlocked)

Maritime claims:
none (landlocked)

Climate:
tropical; modified by altitude; rainy season (October to April)

Terrain:
mostly high plateau with some hills and mountains

Elevation extremes:
Lowest point: Zambezi river 329 m
Highest point: unnamed elevation in Mafinga Hills 2,301 m

Natural resources:
copper, cobalt, zinc, lead, coal, emeralds, gold, silver, uranium, hydropower

Land use:
Arable land: 4.52%
Permanent crops: 0.05%
Other: 95.44% (2011)

Irrigated land:
1,559 sq km (2003)

Total renewable water resources:
105.2 cu km (2011)

Freshwater withdrawal (domestic/industrial/agricultural):
Total: 1.57 cu km/yr (18%/8%/73%)
Per capita: 147 cu m/yr (2002)

Natural hazards:
periodic drought; tropical storms (November to April)

Environment - current issues:
air pollution and resulting acid rain in the mineral extraction and refining region; chemical runoff into watersheds; poaching seriously threatens rhinoceros, elephant, antelope, and large cat populations; deforestation; soil erosion; desertification; lack of adequate water treatment presents human health risks

Environment - international agreements:
Party to: Biodiversity, Climate Change, Climate Change-Kyoto Protocol, Desertification, Endangered Species, Hazardous Wastes, Law of the Sea, Ozone Layer Protection, Wetlands
Signed, but not ratified: none of the selected agreements

Geography - note:
landlocked; the Zambezi forms a natural riverine boundary with Zimbabwe; Lake Kariba on the Zambia-Zimbabwe border forms the world's largest reservoir by volume (180 cu km; 43 cu mi)

People and Society

Nationality:
Noun: Zambian(s)
Adjective: Zambian

Ethnic groups:
African 99.5% (includes Bemba, Tonga, Chewa, Lozi, Nsenga, Tumbuka, Ngoni, Lala, Kaonde, Lunda, and other African groups), other 0.5% (includes Europeans, Asians, and Americans) (2000 Census)

Languages:
11 Bantu languages (Bemba (official) 30.1%, Nyanja (official) 10.7%, Tonga (official) 10.6%, Lozi (official) 5.7%, Chewa 4.9%, Nsenga 3.4%, Tumbuka 2.5%, Lunda (official) 2.2%, Kaonde (official) 2%, Lala 2%, Luvale (official) 1.7%), English (official) 1.7%, other 22.5% (2000 Census)

Religions:
Christian 50%-75%, Muslim and Hindu 24%-49%, indigenous beliefs 1%

Population:
14,222,233 (July 2013 est.)
Country comparison to the world: 70
note: estimates for this country explicitly take into account the effects of excess mortality due to AIDS; this can result in lower life expectancy, higher infant mortality, higher death rates, lower population growth rates, and changes in the distribution of population by age and sex than would otherwise be expected

Age structure:
0-14 years: 46.2% (male 3,300,339/female 3,271,389)
15-24 years: 20% (male 1,423,026/female 1,425,654)
25-54 years: 28.5% (male 2,042,023/female 2,009,511)
55-64 years: 2.9% (male 193,758/female 213,927)
65 years and over: 2.4% (male 147,705/female 194,901) (2013 est.)

Dependency ratios:
Total dependency ratio: 97 %
Youth dependency ratio: 91.8 %
Elderly dependency ratio: 5.2 %
Potential support ratio: 19.4 (2013)

Median age:
Total: 16.7 years
Male: 16.5 years
Female: 16.8 years (2013 est.)

Population growth rate:
2.89% (2013 est.)
Country comparison to the world: 13

Birth rate:
42.79 births/1,000 population (2013 est.)
Country comparison to the world: 5

Death rate:
13.17 deaths/1,000 population (2013 est.)
Country comparison to the world: 19

Net migration rate:
-0.75 migrant(s)/1,000 population (2013 est.)
Country comparison to the world: 144

Urbanization:
Urban population: 39.2% of total population (2011)
Rate of urbanization: 4.15% annual rate of change (2010-15 est.)

Major urban areas - population:
LUSAKA (capital) 1.413 million (2009)

Sex ratio:
At birth: 1.03 male(s)/female
0-14 years: 1.01 male(s)/female
15-24 years: 1 male(s)/female
25-54 years: 1.02 male(s)/female
55-64 years: 0.92 male(s)/female
65 years and over: 0.75 male(s)/female
Total population: 1 male(s)/female (2013 est.)

Mother's mean age at first birth:
19.2 (2007 est.)

Maternal mortality rate:
440 deaths/100,000 live births (2010)
Country comparison to the world: 26

Infant mortality rate:
Total: 68.58 deaths/1,000 live births
Country comparison to the world: 19
Male: 74.16 deaths/1,000 live births
Female: 62.84 deaths/1,000 live births (2013 est.)

Life expectancy at birth:
Total population: 51.51 years
Country comparison to the world: 216
Male: 49.93 years
Female: 53.14 years (2013 est.)

Total fertility rate:
5.81 children born/woman (2013 est.)
Country comparison to the world: 7

Contraceptive prevalence rate:
40.8% (2007)

Health expenditures:
5.9% of GDP (2010)
Country comparison to the world: 113

Physicians density:
0.06 physicians/1,000 population (2006)

Hospital bed density:
2 beds/1,000 population (2010)

Drinking water source:
Improved:
urban: 87% of population
rural: 46% of population
total: 61% of population
Unimproved:
urban: 13% of population
rural: 54% of population
total: 39% of population (2010 est.)

Sanitation facility access:
Improved:
urban: 57% of population
rural: 43% of population
total: 48% of population
Unimproved:
urban: 43% of population
rural: 57% of population
total: 52% of population (2010 est.)

HIV/AIDS - adult prevalence rate:
13.5% (2009 est.)
Country comparison to the world: 6

HIV/AIDS - people living with HIV/AIDS:
980,000 (2009 est.)
Country comparison to the world: 10

HIV/AIDS - deaths:
45,000 (2009 est.)
Country comparison to the world: 10

Major infectious diseases:
Degree of risk: very high
Food or waterborne diseases: bacterial and protozoal diarrhea, hepatitis A, and typhoid fever
Vectorborne diseases: malaria and dengue fever
Water contact disease: schistosomiasis
Animal contact disease: rabies (2013)

Obesity - adult prevalence rate:
3.6% (2008)
Country comparison to the world: 174

Children under the age of 5 years underweight:
14.9% (2007)
Country comparison to the world: 52

Education expenditures:
1.4% of GDP (2008)
Country comparison to the world: 168

Literacy:
Definition: age 15 and over can read and write English
Total population: 61.4%
Male: 71.9%
Female: 51.8% (2007 est.)

School life expectancy (primary to tertiary education):
Total: 7 years
Male: 8 years
Female: 7 years (2000)

Child labor - children ages 5-14:
Total number: 1,000,850
Percentage: 41 %
note: data represents children ages 7-14 (2005 est.)

Unemployment, youth ages 15-24:
Total: 23.4% (2005)
Country comparison to the world: 41

Government

Country name:
Conventional long form: Republic of Zambia
Conventional short form: Zambia
Former: Northern Rhodesia

Government type:
republic

Capital:
Name: Lusaka
Geographic coordinates: 15 25 S, 28 17 E
Time difference: UTC+2 (7 hours ahead of Washington, DC during Standard Time)

Administrative divisions:
10 provinces; Central, Copperbelt, Eastern, Luapula, Lusaka, Muchinga, Northern, North-Western, Southern, Western

Independence:
24 October 1964 (from the UK)

National holiday:
Independence Day, 24 October (1964)

Constitution:
24 August 1991; amended in 1996 to establish presidential term limits

Legal system:
mixed legal system of English common law and customary law; judicial review of legislative acts in an ad hoc constitutional council

International law organization participation:
has not submitted an ICJ jurisdiction declaration; accepts ICCt jurisdiction

Suffrage:
18 years of age; universal

Executive branch:
Chief of state: President Michael Chilufya SATA (since 23 September 2011); Vice President Guy SCOTT (since 30 September 2011); the president is both the chief of state and head of government
Head of government: President Michael Chilufya SATA (since 23 September 2011); Vice President Guy SCOTT (since 30 September 2011)
Cabinet: Cabinet appointed by the president from among the members of the National Assembly
Elections: president elected by popular vote for a five-year term (eligible for a second term); election last held on 20 September 2011 (next to be held in 2016); vice president appointed by the president
Election results: Michael Chilufya SATA elected president; percent of vote - Michael SATA 43.3%, Rupiah BANDA 36.2%, Hakainde HICHILEMA 18.5%, other 2.0%

Legislative branch:
unicameral National Assembly (158 seats; 150 members are elected by popular vote, 8 members appointed by the president, to serve five-year terms)
Elections: last held on 20 September 2011 (next to be held in 2016)
Election results: percent of vote by party - NA; seats by party - PF 60, MMD 55, UPND 28, ADD 1, FDD 1, independents 3; seats not determined 2

Judicial branch:
Highest court(s): Supreme Court (consists of 9 judges)
Judge selection and term of office: Supreme Court judges appointed by the president and ratified by the National Assembly; judge tenure NA
Subordinate courts: High Court; magistrate's courts and local courts

Political parties and leaders:
Alliance for Democracy and Development or ADD [Charles MILUPI]
Forum for Democracy and Development or FDD [Edith NAWAKWI]
Heritage Party or HP [Godfrey MIYANDA]
Movement for Multiparty Democracy or MMD [Nevers MUMBA]
National Restoration Party or NAREP [Elias CHIPIMO]
Party of Unity for Democracy and Development or PUDD [Dan PULE]
Patriotic Front or PF [Michael SATA]
United National Independence Party or UNIP [Tilyenji KAUNDA]
United Party for National Development or UPND [Hakainde HICHILEMA]

Political pressure groups and leaders:
NA

International organization participation:
ACP, AfDB, AU, C, COMESA, EITI (compliant country), FAO, G-77, IAEA, IBRD, ICAO, ICRM, IDA, IFAD, IFC, IFRCS, ILO, IMF, Interpol, IOC, IOM, IPU, ISO (correspondent), ITSO, ITU, ITUC (NGOs), MIGA, MONUSCO, NAM, OPCW, PCA, SADC, UN, UNAMID, UNCTAD, UNESCO, UNHCR, UNIDO, UNISFA, UNMIL, UNMISS, UNWTO, UPU, WCO, WHO, WIPO, WMO, WTO

Diplomatic representation in the US:
Chief of mission: Ambassador Palan MULONDA
Chancery: 2419 Massachusetts Avenue NW, Washington, DC 20008
Telephone: [1] (202) 265-9717 through 9719
FAX: [1] (202) 332-0826

Diplomatic representation from the US:
Chief of mission: Ambassador Mark C. STORELLA
Embassy: Ibex Hill, Lusaka
Mailing address: P. O. Box 31617, Lusaka
Telephone: [260] (0) (211) 357-000
FAX: [260] (0) (211) 357-224

National symbol(s):
African fish eagle

National anthem:
Name: "Lumbanyeni Zambia" (Stand and Sing of Zambia, Proud and Free)
Lyrics/music: multiple/Enoch Mankayi SONTONGA
note: adopted 1964; the melody, from the popular song "God Bless Africa," is the same as that of Tanzania but with different lyrics; the melody is also incorporated into South Africa's anthem

Economy

Economy - overview:
Zambia's economy has experienced strong growth in recent years, with real GDP growth in 2005-12 more than 6% per year. Privatization of government-owned copper mines in the 1990s relieved the government from covering mammoth losses generated by the industry and greatly increased copper mining output and profitability to spur economic growth. Copper output has increased steadily since 2004, due to higher copper prices and foreign investment. In 2005, Zambia qualified for debt relief under the Highly Indebted Poor Country Initiative, consisting of approximately US$6 billion in debt relief. Poverty remains a significant problem in Zambia, despite a stronger economy. Zambia's dependency on copper makes it vulnerable to depressed commodity prices, but record high copper prices and a bumper maize crop in 2010 helped Zambia rebound quickly from the world economic slowdown that began in 2008. Zambia has made some strides to improve the ease of doing business. A high birth rate, relatively high HIV/AIDS burden, and market distorting agricultural policies have meant that Zambia''s economic growth has not dramatically decreased the stubbornly high poverty rate.

GDP (purchasing power parity):
$24.36 billion (2012 est.)
Country comparison to the world: 124
$22.7 billion (2011 est.)
$21.24 billion (2010 est.)
note: data are in 2012 US dollars

GDP (official exchange rate):
$20.52 billion (2012 est.)

GDP - real growth rate:
7.3% (2012 est.)
Country comparison to the world: 24
6.8% (2011 est.)
7.6% (2010 est.)

GDP - per capita (PPP):
$1,700 (2012 est.)
Country comparison to the world: 200
$1,700 (2011 est.)
$1,600 (2010 est.)
note: data are in 2012 US dollars

Gross national saving:
15.3% of GDP (2012 est.)
Country comparison to the world: 98
21% of GDP (2011 est.)
26.4% of GDP (2010 est.)

GDP - composition, by end use:
Household consumption: 59.5%
Government consumption: 26%
Investment in fixed capital: 19.5%
Investment in inventories: 1.1%
Exports of goods and services: 36.6%
Imports of goods and services: -42.7%
(2012 est.)

GDP - composition, by sector of origin:
Agriculture: 20.4%
Industry: 33.2%
Services: 46.4% (2012 est.)

Agriculture - products:
corn, sorghum, rice, peanuts, sunflower seed, vegetables, flowers, tobacco, cotton, sugarcane, cassava (tapioca), coffee; cattle, goats, pigs, poultry, milk, eggs, hides

Industries:
copper mining and processing, construction, foodstuffs, beverages, chemicals, textiles, fertilizer, horticulture

Industrial production growth rate:
4.9% (2012 est.)
Country comparison to the world: 55

Labor force:
5.956 million (2012 est.)
Country comparison to the world: 67

Labor force - by occupation:
Agriculture: 85%
Industry: 6%
Services: 9% (2004)

Unemployment rate:
14% (2006 est.)
Country comparison to the world: 138
50% (2000 est.)

Population below poverty line:
64% (2006)

Household income or consumption by percentage share:
Lowest 10%: 1.2%
Highest 10%: 38.8% (2004)

Distribution of family income - Gini index:
50.8 (2004)
Country comparison to the world: 19
52.6 (1998)

Budget:
Revenues: $4.256 billion
Expenditures: $5.256 billion (2012 est.)

Taxes and other revenues:
20.7% of GDP (2012 est.)
Country comparison to the world: 157

Budget surplus (+) or deficit (-):
-4.9% of GDP (2012 est.)
Country comparison to the world: 164

Public debt:
33.1% of GDP (2012 est.)
Country comparison to the world: 109
29.6% of GDP (2011 est.)

Fiscal year:
calendar year

Inflation rate (consumer prices):
6.6% (2012 est.)
Country comparison to the world: 173
8.7% (2011 est.)

Central bank discount rate:
8.39% (31 December 2009)
Country comparison to the world: 12
14.49% (31 December 2008)

Commercial bank prime lending rate:
12.14% (31 December 2012 est.)
Country comparison to the world: 20
18.84% (31 December 2011 est.)

Stock of narrow money:
$2.187 billion (31 December 2012 est.)
Country comparison to the world: 122
$1.631 billion (31 December 2011 est.)

Stock of broad money:
$4.906 billion (31 December 2012 est.)
Country comparison to the world: 129
$4.075 billion (31 December 2011 est.)

Stock of domestic credit:
$3.836 billion (31 December 2012 est.)
Country comparison to the world: 127
$3.293 billion (31 December 2011 est.)

Market value of publicly traded shares:
$4.009 billion (31 December 2011)
Country comparison to the world: 92
$2.817 billion (31 December 2010)
$2.804 billion (31 December 2009)

Current account balance:
-$1.048 billion (2012 est.)
Country comparison to the world: 113
$215 million (2011 est.)

Exports:
$8.589 billion (2012 est.)
Country comparison to the world: 99
$8.672 billion (2011 est.)

Exports - commodities:
copper/cobalt, cobalt, electricity; tobacco, flowers, cotton

Exports - partners:
China 42.2%, South Africa 7.2%, Democratic Republic of the Congo 7.2%, South Korea 5.3%, India 4.5%, Egypt 4.5%, UAE 4.4% (2012)

Imports:
$7.361 billion (2012 est.)
Country comparison to the world: 110
$6.454 billion (2011 est.)

Imports - commodities:
machinery, transportation equipment, petroleum products, electricity, fertilizer, foodstuffs, clothing

Imports - partners:
South Africa 36.2%, Democratic Republic of the Congo 21.3%, China 10.1%, Kuwait 5.7% (2012)

Reserves of foreign exchange and gold:
$3.042 billion (31 December 2012 est.)
Country comparison to the world: 110
$2.324 billion (31 December 2011 est.)

Debt - external:
$5.048 billion (31 December 2012 est.)
Country comparison to the world: 120
$4.36 billion (31 December 2011 est.)

Stock of direct foreign investment - at home:
$NA

Stock of direct foreign investment - abroad:
$NA

Exchange rates:
Zambian kwacha (ZMK) per US dollar -
5.1 (2012 est.)
4.9 (2011 est.)
4,797.1 (2010 est.)
5,046.1 (2009)
3,512.9 (2008)

Energy

Electricity - production:
10.2 billion kWh (2009 est.)
Country comparison to the world: 92

Electricity - consumption:
7.704 billion kWh (2009 est.)
Country comparison to the world: 96

Electricity - exports:
110 million kWh (2010)
Country comparison to the world: 69

Electricity - imports:
33 million kWh (2010 est.)
Country comparison to the world: 101

Electricity - installed generating capacity:
1.679 million kW (2009 est.)
Country comparison to the world: 109

Electricity - from fossil fuels:
0.4% of total installed capacity (2009 est.)
Country comparison to the world: 205

Electricity - from nuclear fuels:
0% of total installed capacity (2009 est.)
Country comparison to the world: 207

Electricity - from hydroelectric plants:
99.6% of total installed capacity (2009 est.)
Country comparison to the world: 4

Electricity - from other renewable sources:
0% of total installed capacity (2009 est.)
Country comparison to the world: 207

Crude oil - production:
0 bbl/day (2011 est.)
Country comparison to the world: 208

Crude oil - exports:
0 bbl/day (2009 est.)
Country comparison to the world: 208

Crude oil - imports:
10,790 bbl/day (2009 est.)
Country comparison to the world: 76

Crude oil - proved reserves:
0 bbl (1 January 2013 est.)
Country comparison to the world: 207

Refined petroleum products - production:
9,664 bbl/day (2008 est.)
Country comparison to the world: 105

Refined petroleum products - consumption:
19,260 bbl/day (2011 est.)
Country comparison to the world: 130

Refined petroleum products - exports:
21.18 bbl/day (2009 est.)
Country comparison to the world: 121

Refined petroleum products - imports:
17,570 bbl/day (2008 est.)
Country comparison to the world: 108

Natural gas - production:
0 cu m (2010 est.)
Country comparison to the world: 211

Natural gas - consumption:
0 cu m (2010 est.)
Country comparison to the world: 211

Natural gas - exports:
0 cu m (2010 est.)
Country comparison to the world: 209

Natural gas - imports:
0 cu m (2010 est.)
Country comparison to the world: 82

Natural gas - proved reserves:
0 cu m (1 January 2012 est.)
Country comparison to the world: 208

Carbon dioxide emissions from consumption of energy:
2.416 million Mt (2010 est.)
Country comparison to the world: 146

Communications

Telephones - main lines in use:
85,700 (2011)
Country comparison to the world: 149

Telephones - mobile cellular:
8.165 million (2011)
Country comparison to the world: 87

Telephone system:
General assessment: among the best in sub-Saharan Africa
Domestic: high-capacity microwave radio relay connects most larger towns and cities; several cellular telephone services in operation and network coverage is improving; domestic satellite system being installed to improve telephone service in rural areas; Internet service is widely available; very small aperture terminal (VSAT) networks are operated by private firms
International: country code - 260; satellite earth stations - 2 Intelsat (1 Indian Ocean and 1 Atlantic Ocean), 3 owned by Zamtel (2010)

Broadcast media:
state-owned Zambia National Broadcasting Corporation (ZNBC) operates 1 TV station and is the principal local-content provider; several private TV stations; multi-channel subscription TV services are available; ZNBC operates 3 radio networks; about 2 dozen private radio stations; relays of at least 2 international broadcasters are accessible in Lusaka and Kitwe (2007)

Internet country code:
.zm

Internet hosts:
16,571 (2012)
Country comparison to the world: 122

Internet users:
816,200 (2009)
Country comparison to the world: 105

Transportation

Airports:
88 (2013)
Country comparison to the world: 63

Airports - with paved runways:
Total: 8
Over 3,047 m: 1
2,438 to 3,047 m: 3
1,524 to 2,437 m: 3
914 to 1,523 m: 1 (2013)

Airports - with unpaved runways:
Total: 80
2,438 to 3,047 m: 1
1,524 to 2,437 m: 5
914 to 1,523 m: 53
Under 914 m:
21 (2013)

Pipelines:
oil 771 km (2013)

Railways:
Total: 2,157 km
Country comparison to the world: 69
Narrow gauge: 2,157 km 1.067-m gauge
note: includes 891 km of the Tanzania-Zambia Railway Authority (TAZARA) (2008)

Roadways:
Total: 91,440 km
Country comparison to the world: 52
Paved: 20,117 km
Unpaved: 71,323 km (2001)

Waterways:
2,250 km (includes Lake Tanganyika and the Zambezi and Luapula rivers) (2010)
Country comparison to the world: 39

Ports and terminals:
Mpulungu

Military

Military branches:
Zambian National Defense Force (ZNDF): Zambia Army, Zambia Air Force, National Service (paramilitary youth organization) (2012)

Military service age and obligation:
national registration required at age 16; 18-25 years of age for male and female voluntary military service (16 years of age with parental consent); no conscription; Zambian citizenship required; grade 12 certification required; mandatory HIV testing on enlistment; mandatory retirement for officers at age 65 (Army, Air Force) (2012)

Manpower available for military service:
Males age 16-49: 3,041,069
Females age 16-49: 2,948,291 (2010 est.)

Manpower fit for military service:
Males age 16-49: 1,745,656
Females age 16-49: 1,688,670 (2010 est.)

Manpower reaching militarily significant age annually:
Male: 158,592
Female: 158,805 (2010 est.)

Military expenditures:
1.8% of GDP (2012)
Country comparison to the world: 79

Transnational Issues

Disputes - international:
in 2004, Zimbabwe dropped objections to plans between Botswana and Zambia to build a bridge over the Zambezi River, thereby de facto recognizing a short, but not clearly delimited, Botswana-Zambia boundary in the river

Refugees and internally displaced persons:
Refugees (country of origin): 14,871 (Democratic Republic of the Congo); 5,963 (Rwanda) (2012)

Illicit drugs:
transshipment point for moderate amounts of methaqualone, small amounts of heroin, and cocaine bound for southern Africa and possibly Europe; a poorly developed financial infrastructure coupled with a government commitment to combating money laundering make it an unattractive venue for money launderers; major consumer of cannabis

Flag of Zambia



Flag description:
green field with a panel of three vertical bands of red (hoist side), black, and orange below a soaring orange eagle, on the outer edge of the flag; green stands for the country's natural resources and vegetation, red symbolizes the struggle for freedom, black the people of Zambia, and orange the country's mineral wealth; the eagle represents the people's ability to rise above the nation's problems